Slow Roasted Leg of Lamb

Lunch | French

Prep time: 20 min Cook time: 4 min Servings: 4

This is one of the most forgiving dishes you can make in the oven. A bone-in leg of lamb goes in at 150°C, sealed tightly under foil, and sits for four hours while the collagen slowly breaks down and the meat becomes tender enough to pull apart with forks. Underneath the lamb, thirty cloves of garlic confit in the rendered fat and beef stock, transforming from sharp and pungent into something sweet, jammy and almost creamy. At the end, the garlic, onions and pan juices get blended into a sauce that’s rich without any of the harshness you’d expect from that much garlic.

The process is almost entirely hands-off once it’s in the oven. The two things that matter most are getting a tight seal on the pan at the start so the lamb braises in its own steam and juices, and removing the foil for the final 20 minutes to get colour on the outside. I use beef stock rather than lamb stock because it gives a deeper, more robust base to the sauce.

Start it before lunch and it will be ready by dinner.

Ingredient Notes

Lamb leg, bone in: The bone is important here. It conducts heat into the center of the meat and contributes collagen and gelatin to the pan juices as it cooks, which gives the sauce its body and gloss. A 1.5kg of bone-in leg comfortably feeds four. If your butcher only has smaller half-legs, two of those work just as well with the same cooking time. Ask for the aitch bone removed if you want easier carving at the table.

Garlic: Thirty cloves sounds like a lot but don’t be put off. Low, slow heat completely transforms garlic: the allicin compounds that give raw garlic its sharpness break down over time and what’s left is mild, sweet and almost nutty. Peeling thirty cloves is the most tedious part of the prep. To speed it up, blanch the unpeeled cloves in boiling water for 30 seconds and the skins slip straight off. Pre-peeled cloves from the supermarket also work fine here.

Beef stock: I use beef stock rather than lamb stock because it gives a darker, more robust base that stands up to the richness of the confit garlic sauce. A good quality store-bought stock works well. If you want more depth, a veal or brown chicken stock will both give excellent results. The stock also acts as the braising liquid that keeps the lamb moist during the four-hour cook, so don’t reduce the quantity. If your stock is very salty, season the lamb more conservatively at the start.

Equipment

Chopping board
Chef’s knife
Large heavy-based roasting pan with high sides
Baking paper
Aluminium foil
Stick (immersion) blender or jug blender
Measuring jug
Ladle
2 carving forks
Tongs

Ingredients

1.5kg (3.3 lbs) lamb leg, bone in
sea salt and black pepper, to season
30 cloves garlic, peeled
2 red onions, quartered
8 sprigs rosemary
4 sprigs thyme
3 fresh bay leaves
750ml (3 cups) beef stock

Directions

Prep the lamb
Preheat the oven to 150°C fan forced (300°F).
Season the lamb with salt on all sides. Place the garlic in the base of a large heavy-based roasting pan, then top with the lamb.
Place the onions, rosemary, thyme and bay leaves in around the lamb, season with some black pepper, then pour over the stock.
Place a piece of baking paper over the top of the lamb, then cover the pan tightly with foil.
Roast the lamb
Roast the lamb for 4 hours.
Increase the oven temperature to 200°C fan forced (390°F).
Remove the foil from the pan and roast for a further 20 minutes, until the lamb skin begins to brown and crispen. Transfer the lamb to a serving dish and keep warm.
Make pan sauce and serve
Remove all the hard herbs from the pan, then transfer the pan sauce, with the garlic and onions, to a jug and allow the fat to settle to the top.
Skim off the fat, then puree with a stick (immersion) blender until smooth.
Pour the sauce over the lamb and pull the meat apart from the bone with carving forks to serve.

Recipe notes

Chef Tips

Seal the pan tightly before it goes in the oven

Make sure the foil is sealed properly around your pan before it goes in the oven. If steam escapes during the four hours, the braising liquid evaporates, the lamb risks drying out and the garlic can scorch on the base of the pan. I just take one layer of foil (more than enough to cover the top) and then crimp the sides down over the edge until each section is sealed. Don’t be tempted to lift the foil and check during the cook.

Let the fat settle before you make the sauce

After transferring the pan juices to a jug, give them at least 10 minutes to settle before skimming. The rendered fat will rise to the top as a distinct layer and you can lift it off cleanly with a ladle or spoon. If you blend before skimming, the fat emulsifies back into the sauce and you’ll get a greasy result. A fat separator jug makes this step easy if you have one. Don’t discard every last drop of fat though. A small amount left in the sauce adds richness and helps it coat the lamb properly.

Storage

Pull any leftover lamb off the bone and store it in the sauce in an airtight container in the fridge for up to 3 days. The sauce keeps the meat moist as it cools and reheats. Warm it gently in a covered saucepan over low heat with a splash of water if the sauce has thickened. The lamb also freezes well for up to 3 months. Freeze the meat and sauce together so nothing dries out.

FAQs

Can I make this ahead of time? Yes. Slow roast the lamb as per the recipe, then leave it covered and rested at room temperature for up to 2 hours, or in a cooler (esky) for longer. When you’re ready to serve, remove the foil, return it to a 200°C oven for 20 minutes to develop colour and heat through. Make the sauce while it’s in the oven for the final blast.

How do I know when the lamb is done? With slow-roasted lamb you’re not chasing a specific internal temperature the way you would with a medium-rare leg. You’re waiting for the collagen to fully break down, which makes the meat pull-apart tender. After 4 hours at 150°C it should be there. Push a carving fork into the thickest part: if it slides in easily and the meat starts to yield, it’s ready. If it resists, cover it back up and give it another 30 minutes.

Can I use lamb shoulder instead of leg? Absolutely, shoulder is a great cut for slow roasting. It has more intramuscular fat and connective tissue than the leg, which means it becomes even more tender and flavoursome after a long braise. Use the same temperature, the same cooking time and the same sauce method. A bone-in shoulder of a similar weight will give you an outstanding result.