Roasted Leg Lamb Potatoes

The smell of roasting lamb drifting through the house on a Sunday afternoon is one of those kitchen moments that feels like home before you even realize why. My mother-in-law taught me her method for getting those golden potatoes to crisp up perfectly while the lamb rests, a small detail that somehow makes the whole meal feel complete.

Last Easter, my sister-in-law was skeptical about roasting lamb, worried she would overcook it. We hovered around the oven with our meat thermometer, and when we sliced into that perfectly pink medium-rare center, she looked at me like I had revealed some grand kitchen secret rather than just followed a simple temperature guide.

Ingredients

• 1 (2–2.5 kg) bone-in leg of lamb: The bone adds depth of flavor and helps keep the meat juicy during roasting
• 4 garlic cloves, sliced: Fresh garlic tucked into small incisions infuses the meat from within
• 2 tbsp fresh rosemary, chopped: Woody and piney, rosemary pairs naturally with lamb
• 2 tbsp fresh thyme, chopped: Adds an earthy, floral note that balances the richness
• 2 tsp coarse salt: Essential for seasoning and helping form a nice crust
• 1 tsp freshly ground black pepper: Provides a subtle heat that cuts through the fat
• 2 tbsp olive oil: Helps the herb rub adhere and promotes even browning
• 1 lemon, zested and juiced: Brightens the rich flavors and cuts the natural sweetness
• 1.5 kg Yukon Gold or waxy potatoes, peeled and quartered: These hold their shape and develop a creamy interior with crisp skin
• 2 tbsp olive oil for potatoes: Coats the potatoes for even roasting and golden color
• 1 tsp coarse salt for potatoes: Season the potatoes generously as they need it to stand up to the lamb
• ½ tsp freshly ground black pepper for potatoes: Adds depth to the roasted potato flavor
• 1 tbsp fresh rosemary, chopped for potatoes: Echoes the lamb seasoning for harmony
• 1 cup lamb or chicken stock (optional): Creates a simple pan jus during the final minutes
• Fresh parsley, chopped for serving: Adds a fresh pop of color and bright flavor

Instructions

Preheat and prepare the lamb:

Set your oven to 200°C (400°F) and pat the leg of lamb thoroughly dry with paper towels. Using a sharp knife, make small slits all over the meat and slip the garlic slices into each opening, pushing them down as far as they will go.

Make the herb rub:

In a small bowl, combine the rosemary, thyme, salt, pepper, olive oil, lemon zest, and juice until it forms a paste. Massage this mixture generously over the entire surface of the lamb, working it into all the crevices.

Set up for roasting:

Place the seasoned lamb on a wire rack in a large roasting pan, fat side up. This allows air circulation and lets the potatoes catch the flavorful drippings below.

Season the potatoes:

In a separate bowl, toss the quartered potatoes with olive oil, salt, pepper, and the additional rosemary until evenly coated. Arrange them around the lamb in the roasting pan or in a separate tray if they do not all fit.

Roast to perfection:

Place the pan in the oven and roast for about 1 hour 20 minutes for medium-rare, which means an internal temperature of 55–60°C. Flip the potatoes once halfway through so they brown evenly on all sides.

Add the jus and rest the meat:

During the final 20 minutes of roasting, pour the stock into the bottom of the pan if you want a light sauce. When done, remove the lamb from the oven and tent it loosely with foil, letting it rest for 15–20 minutes so the juices redistribute.

Crisp the potatoes and serve:

While the lamb rests, increase the oven to 220°C (425°F) and return the potatoes for 5–10 minutes until they are golden and crispy. Slice the lamb against the grain and serve with the roasted potatoes, drizzled with any pan juices and sprinkled with fresh parsley.

Save

There is something deeply satisfying about bringing a whole roasted leg of lamb to the table, the way it becomes the center of conversation and draws everyone in. My daughter now asks for this on her birthday, claiming no restaurant version has ever compared to the one we make together at home.

Marinating for Extra Flavor

After years of making this roast, I discovered that marinating the lamb overnight transforms a great meal into something exceptional. The herb rub penetrates deeper into the meat, resulting in layers of flavor throughout rather than just on the surface.

Choosing the Right Cut

A bone-in leg of lamb may seem intimidating, but the bone acts as a natural heat conductor and adds incredible depth to the pan drippings. If you cannot find a whole leg, ask your butcher for a half leg or sirloin portion, adjusting the cooking time accordingly.

Perfecting the Potatoes

The potatoes might seem like a side note, but they are often what guests remember most. Waxy potatoes like Yukon Gold hold their shape beautifully and develop that irresistible creamy interior while the outside crisps in the rendered lamb fat.

• Do not overcrowd the roasting pan or the potatoes will steam instead of crisp
• Space the potatoes in a single layer for the best browning
• Give the potatoes a final high-heat blast while the lamb rests

Save

This roast has become our celebration meal, the one that makes any Sunday feel special and any holiday complete.

Recipe FAQs

→ How long should the leg of lamb rest after roasting?

Resting the lamb for 15-20 minutes allows the juices to redistribute, ensuring moist and tender slices.

→ What internal temperature indicates medium-rare doneness?

Cook until the lamb reaches an internal temperature of 55–60°C (130–140°F) for medium-rare.

→ Can I prepare the herb rub in advance?

Yes, marinating the lamb with the herb rub overnight intensifies the flavors deeply.

→ What type of potatoes work best for roasting?

Yukon Gold or other waxy potatoes hold their shape well and become perfectly crispy when roasted.

→ How is the light jus made during roasting?

Adding lamb or chicken stock to the pan in the last 20 minutes creates a flavorful jus from the pan drippings.

→ Are there suitable herb alternatives to rosemary?

Oregano or a pinch of chili flakes can replace rosemary for a different aromatic twist.