Roast lamb with fresh mint topping

Roast lamb with fresh mint topping, sticky roasted onions, gravy and crispy potatoes

I love cooking lamb at Christmas – why wouldn’t you when NZ lamb is the best you can get anywhere in the world? Even though it’s a roast, I’ve freshened it up so it suits a festive kiwi summer feast – lots of fresh herbs and a nice zingy dressing. And the mint and springy-onion garnish tops it off! Of course, I’ve still included a beautiful gravy and my ‘world famous in NZ’ crispy potatoes for those who want them (highly recommended.) This meal is perfect with a salad, and best finished off with one of my delicious desserts (click here to see them).

Prep time: 35mins, plus overnight for marinating if possible
Cooking time: 2 hours, plus resting
Skill level: Easy peasy! It may look like a lot of writing below, but it’s just me explaining things in detail to make it clear and easy to understand. It’s really just a fancy-looking meal made up of several simple components anyone can make.


1 Quality Mark whole lamb leg, bone-in
1 bag French (or pickling) onions, peeled
2 cups chicken stock (for the gravy)
¼ cup flour (for the gravy)

5 cloves garlic, crushed
2 tablespoons Dijon mustard
4 anchovy fillets, finely chopped
½ cup fresh rosemary, finely chopped
2 tablespoons dried marjoram
Zest of 2 lemons
2 tablespoons butter, softened
1 tablespoon lemon juice
3 tablespoons olive oil

Fresh mint topping
¾ cup crème fraiche
1 bunch fresh mint, leaves picked
1 clove garlic, crushed
2 tablespoons olive oil
1 tablespoon red or white wine vinegar, or lemon juice

Springy garnish
2-3 spring onions, opened out and sliced into very thin long strips
1 bunch fresh mint, leaves picked


THE DAY BEFORE (if possible)

Place the lamb leg fat-side up on a clean chopping board and pat dry with a paper towel. Using a sharp knife, make a series of shallow cuts into the lamb a few cm apart, so the marinade flavours can really get in there.

Combine the marinade ingredients together and spread over the lamb, rubbing it into the cuts. Wrap the lamb in clingfilm and refrigerate, preferably overnight or for at least 2 hours.


Remove the marinated lamb from the fridge 30 minutes before cooking. Preheat the oven to 180c (or 170c fan bake). Place the lamb in a roasting dish fat side up and season with lots of salt and pepper. Transfer to the oven and bake uncovered for 25-30 mins per 500g for medium (or 20-25 mins per 500g for rare/medium-rare). Baste once of twice with the lovely oil and juices in the bottom of the pan.

With 1 hour remaining, add the onions to the roasting dish and shuffle them around to coat them with some oil from the bottom of the pan. Season them, and turn them over once while cooking.

Remove from the oven, transfer the lamb and onions to a wooden board/warm plate and cover loosely with foil. Leave to rest for 20-30 minutes.

Spring onion and mint garnish
While the lamb is cooking, submerge the sliced spring onions and mint leaves in a bowl filled with lots of ice and water. Leave in the fridge for at least an hour – the spring onions will then curl up into little springy coils which look very cool and summery as garnish. The thinner and longer you’ve cut them, the better! Keep adding more ice if you need to leave it in the fridge for a few hours. When you’re ready to serve, drain and rest on paper towels.

Fresh mint topping
Combine all ingredients in a food processor, mortar and pestle, or mince everything finely with a knife and mix well. Taste and season with salt and pepper. Keeps in the fridge for a couple of hours before serving.

To make a rich gravy while the lamb rests, tip most of the fat from the lamb roasting dish, leaving the meat juices and all that good stuff on the bottom.

Combine the flour with 1/2 cup water and add to the roasting dish, with remaining meat juices, on the stovetop over a medium heat. Add chicken stock, stirring all the time with a wooden spoon, for about 5-10 minutes until thickened. Make sure you scrape all the caramelised meat juices and onion off the bottom to add flavour. Strain if you like before pouring into a jug.

To serve
Place the rested lamb on a platter or board and drizzle with the fresh mint topping. Garnish with the springy onions and mint. Arrange the sticky roasted onions around the lamb. Serve with the gravy and Chelsea’s crispy roast potatoes (click here for the recipe). This meal is lovely with even just some BBQ’d asparagus dressed with a little lemon zest, salt, pepper, avocado oil and fresh parsley. Or a nice salad (great recipe here) – or vegetables.

These days, when I’m not writing cookbooks and dashing around the country doing foodie things, I spend most of my time gangling around in my little kitchen, creating new and exciting recipes to inspire home cooks, like you.
  1. Dave Adams Reply
    We own a life style block and raise our own meat including lamb. The kids and grandkids are normally here for Xmas however I think is going to be cooked for them before Xmas. Thanks for the recipe.
  2. Kerry Hamilton Reply
    Made this for friends for a Christmas get together - It was brilliant. I am not normally a good cook but the recipe was easy to follow. It turned our great and we all had a really good night. Thanks Chelsea for giving me the courage to make a super dinner for my friends. Kerry
    • Chelsea Winter Reply
      Cheers Kerry, glad to hear it. And you're welcome!
  3. angela Reply
    Wow, this lamb is amazing! It came up under a search for lamb and mint. My 11 year old meat lover scooped out the marrow, picked off all the marinade-encrusted fat and gnawed the bone. It was festive, smelled great at every stage and we will save it for another year. We live in Spain, by the way.
    • Chelsea Winter Reply
      Thanks for that message Andrea - holy moly, Spain - that's super!
  4. Kelly Reply
    Hi Chelsea just wondering what you mean by putting onions in for the one hour remaining, when it says to only cook the lamb for 25-30 mins? Sorry if that's a stupid question but just wanted to check what you mean by that?
    • Chelsea Winter Reply
      Hi Kelly, cook the lamb for 20-25 minutes per 500g :)
  5. malissa Reply
    Your awesome
  6. Ellaine Reply
    Hands down, the best roast lamb recipe I have ever tried. How am I going to tell my Mum?
  7. nicky Reply
    Wonderful marinade for roast. Im pretty fussy with my farm roasts but this is my hands down fav.
  8. Alanna Begg Reply
    I've never been one for the kitchen, i never cook but i came across this recipe in the meat magazine and just had to give it a go. Have now tried and tested it twice, and had rave reviews both times. The second time the boys were left picking off any leftover meat they could. Gonna be trying out more of your recipes now, Thanks Chelsea. :)
  9. Laressa Reply
    Hi Chelsea, is it possible to make the marinade and mint topping without garlic or do you recommend a substitute? Thanks!
  10. Teresa Reply
    Help! My partner has had the oven on grill for the whole cooking time can I save this?!
  11. Natasha Reply
    I made this with a HUGE lamb leg! I invited my in laws for dinner and my MIL said she could smell it from down the road! I must say it cost a fair bit for the marinade ingredients, BUT TOTALLY WORTH IT! I'm usually the biggest Scrooge but in this case it was my very first roast I've ever cooked and I did not want to fail. Thanks for a fabulous recipe Chelsea! Much appreciated :) I'm going to start saving for your new cookbook now
  12. Cherie Reply
    Kia ora Chelsea Lastnight I cooked for the family which includes 2 Chefs. I was nervous. I am not reknowned for any cooking. I cooked yr Roast Lamb with Fresh mint topping. The recipe was easy to follow. OMG it was amazing, the marinade was to die for, everyone loved and the chefs in the family said it was the best Lamb they have ever tasted and are going to use yr marinade. Thank you so much!
  13. SGB Reply
    I'm making this for family and friends for our Sunday Roast this coming weekend - and it's the fourth time I'll be making it. This is hands-down the best ever lamb roast recipe! I do a slight variation on the cooking of the lamb - I pop the marinated lamb leg into a large oven bag and bake it in the oven on 140C for about 6 hours (for a 2.5kg leg of lamb), take it out of the oven and let it rest for about 20-30 mins. Then I just snip off a corner of the oven bag and pour the meat juices into a pot and make the gravy :) The marinade might seem to others a bit laborious and expensive but trust me when I say the flavour it adds to the meat juices is out of this world delicious :) Thanks Chelsea!
  14. Shelley Reply
    Delicious!! Everybody loved this, was a hit for mothers day and nice and easy. Roast potatoes also turned out amazing!! Thank you!
  15. Sheri Glover Reply
    Chelsea, I used the marinade part of your recipie minus the anchovies and my dinner companions that night raved so I'm doing it again! Thanks for the recipient and inspiration.
  16. Veronica Reply
    I made this and it was fantastic. I want to make it again for friends, but one of them eats gluten free. Would the gravy be OK with gluten free flour or should I use corn flour?
  17. Sue Reply
    A wonderful recipe and had rave reviews from guests. I covered the roast with tinfoil after the first hour, to prevent the top from being too burnt and used more flour for the gravy to make it thicker. Excellent and accurate recipe to follow.
  18. Jane Reply
    This is the MOST amazing lamb I have ever tasted. I discovered your recipes after having an incredible CW meal at a friends. Our family is totally hooked and love that these are recipes that use 'normal' ingredients and have such incredible flavours, no trekking to some exclusive store to ask for some expensive ingredient that I've never heard of. Im having so much fun doing family meals which is a job I have not enjoyed much to date. THANKS!!!
  19. Angela C Reply
    This was divine. The only thing I'd say is don't whiz the mint topping for very long, as the creme fraiche turns to butter. I cut up the left overs, made a thick gravy out of the left over gravy and some stock, stirred in some baby peas, put it in a pie, spread the mint topping over the top, put the pie lid on and it was the best damned lamb pie I've ever had. Thanks Chelsea!
  20. Raneen Reply
    Chelsea Winter this recipe is deeevineeee!!! Oh my goodness I’m just speechless ?. I had my in laws over for a Christmas Eve dinner and I doubled the recipe (so two lamb legs). I was so excited making the marinate as it smelt and looked amazing! Once cooked it tasted sooo incredibly delicious and it was falling off the bone. Everyone was raving about it and asking for the recipe and I only have a little bit left over even though I had other dishes. It was definitely the star of the dinner party today! Thank you for making these amazing recipes that are oh so easy to follow! Merry Christmas.
  21. Joanne Reply
    Hi Chelsea Would it b ok to slow roast it for 5 hours instead of 180 for 2 hours? Would o have to do anything different?
  22. Ngatee Reply
    Hi everyone! Letting you know that I followed this lamb recipe but wrapped in tinfoil overnight and slow roasted it for 6 hours @ 130C the next day (with tinfoil on). It turned out so perfectly tender and delicious. Melt in your mouth. I added a half cup of water to the roasting dish and made all the goodness into a gravy at the end. Thanks so much Chelsea this was so easy but a real crowd favourite!

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