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Slow Roasted Leg of Lamb

Slow Roasted Leg of Lamb

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I remember my mom making us this Slow Roasted Leg of Lamb every year during Christmas. She didn’t follow any recipes, she added ingredients as she went along and amazing how it all still tasted so good.

Slow Roasted Leg of Lamb

The recipe I’ve used for this Slow Roasted Leg of Lamb is almost exactly like hers. The only thing I did differently was the addition of the Dijon Mustard and the vegetable stock. 

She did make a gravy too but I just did my own thing as far as that is concerned. My kids are crazy abour roast lamb. When I do make a Roast Lamb they don’t need an invitation to the dinner table. 

Once they smell it in the oven, I keep getting asked “What time is dinner going to be ready”.  So you can imagine the torture because this roast does take a whole 3 hours to cook and dinner is definitely not served at 3pm in the afternoon.

Cooking the Lamb

It can seem a little intimidating roasting a whole leg of lamb. But it real is not that difficult. I look for simple ways of doing things and that’s exactly how I did this too.

For me it’s all about the end result. If I get a flavorsome lamb that’s still soft and tender I’m all good. I don’t care how it’s cooked, after all it’s about the end result.

Looking back my mum didn’t use any fancy methods or techniques and her lamb was always delicious and tender.

All you do is mix the ingredients for the marinade in a bowl. Set it aside. Then you make little slits in the lamb and stuff the cloves, garlic and rosemary in. This does give the lamb a lovely fragrance.

It goes into the oven for 3 hours, you don’t have to even worry about it for at least 2 hours. Give it a turn only once and dinner is served.

The Gravy

I used some vegetable stock when cooking the lamb. You can use other stock if you wish. This together with the drippings from the lamb created an amazing gravy for the lamb.

If you are ok with using alcohol you can mix some sherry and dijon mustard for the gravy. Like this recipe from Food Network.

Cooking Times

For the leg of lamb it takes about 25-30 minutes per 500 gram. I did cook mine on a lower temperature so it did take longer. Besides I like to fully cook my lamb. 

My kids will not eat it it they see pink bits of lamb. However, you can use your discretion in terms of cooking.

When I sliced the lamb it did look a very pale pink but it was moist and tender. It certainly wasn’t rare or medium, I think it was more on the side of well done.

If you prefer more pink meat you can cook your lamb for a shorter period of time.  Once the lamb is cooked you have to rest it for at least 15 minutes before slicing.

I do hope you enjoy this recipe. I would love to hear your comments.

More Holiday Recipes to try:

Perfect Garlic Herb Roast Chicken

Lemon Roast Potatoes

Perfect Roast Vegetable

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5 from 2 votes

Slow Roasted Leg of Lamb

This leg of lamb is so full of flavor and cooked perfectly tender
Course Main Course
Keyword holiday recipes, lamb recipes, roast lamb, slow roasted lamb
Prep Time 15 minutes
Cook Time 3 hours


  • 1.5 kg leg of lamb
  • 1 tbsp dijon mustard
  • 2 tsp fresh thyme leaves
  • 5 large cloves garlic 2 minced and 3 chopped into 4 pieces each
  • 3 sprigs rosemary
  • 12 cloves
  • 1 cup vegetable stock
  • 1/2 tsp salt
  • 1/2 tsp pepper


  • 1 tbsp butter
  • 1 tbsp cake wheat flour or all purpose flour
  • pan drippings


  • Preheat oven to 180 degrees Celsius
  • Bring lamb to room temperature. Pat lamb dry with paper towels.
  • In a small bowl, combine the thyme, mustard, minced garlic, salt and pepper. Set aside
  • Use a sharp knife and make deep indents in the lamb. About 6 on each side
  • Stuff a piece of garlic, a small piece of rosemary and a clove in each indent
  • Rub the marinade all over the lamb
  • Place some foil in a roasting pan. Place the lamb inside, fatty side up and pour the stock into the pan. Cover with a piece of foil and cook in the oven for 2 hours
  • After 2 hours remove the foil and flip the lamb over. Cook for another 1 hour or until cooked to your liking


  • Once the lamb is cooked remove the lamb from the pan and place on a platter or cutting board
  • Heat a tablespoon of butter in a pan. Add 1 tablespoon flour and whisk for about a minute. Add the liquid from the roasting pan and a half cup of water. Whisk until it thickens
  • Strain and set aside until serving


  1. If you are cooking a bigger leg of lamb you will need to increase the cooking time. I would suggest at least 30 minutes extra per 500g
  2. You can marinate your lamb the night before and cook the next day
  3. I didn't add a lot of salt to the marinade because the stock also had salt. You can increase the salt if you wish
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Sunday 26th of December 2021

I made this for Christmas lunch and it was amazing! The meat was so soft and succulent yet still well done, and so flavourful! Thank you for all of your awesome recipes, they are so easy and packed with flavour. Always my go-to blog


Tuesday 1st of February 2022

Thank you Dineshree. That's wonderful. Im glad you enjoyed it:-)


Tuesday 5th of January 2021

Hi Lorraine

Cooked your slow roasted lamb on Sunday as a treat for my daughter who went back to Cape Town yesterday. It was a great success and will now be a permanent when we have leg of lamb! Thanks again for all your delicious recipes.

Warm regards Trevor


Tuesday 5th of January 2021

Thank you so much Trevor. I appreciate the feedback and so happy to hear that your lamb was a success. Hope you enjoyed the time spent with your daughter. All the best for 2021:-)

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