Roasted Leg Lamb Potatoes

The smell of rosemary and garlic hitting that hot oven still takes me back to my first Easter dinner attempt. I was twenty-two, nervous about cooking for my in-laws, and ended up checking the meat thermometer every five minutes like it held the secrets to the universe. The lamb came out perfectly medium-rare anyway, and Ive learned since that the oven knows what its doing if you just trust it. Now this roast is my go-to for celebrations and lazy Sundays alike.

Last spring my neighbor smelled this roasting through our open kitchen window and actually knocked on the door to ask what was happening in there. We ended up eating together on the back porch, and theres something about a leg of lamb that just pulls people to the table. The potatoes might have been the real star though, golden and crisp-edged from swimming in all that flavorful fat.

Ingredients

• 1 (2–2.5 kg / 4.5–5.5 lb) bone-in leg of lamb, trimmed: The bone adds incredible flavor and helps the meat cook evenly, plus it looks impressive coming out of the oven
• 4 cloves garlic, sliced: Slip these into little incisions all over the meat so the garlic mellows and sweetens as it roasts from the inside out
• 2 tablespoons fresh rosemary, chopped: Woody herbs like rosemary can handle the long roasting time without losing their punchy aromatic qualities
• 2 tablespoons fresh thyme, chopped: Thyme adds this earthy undertone that balances the stronger rosemary perfectly
• 2 teaspoons kosher salt: Dont skimp here, proper seasoning is what transforms a roast from edible to unforgettable
• 1 teaspoon freshly ground black pepper: Freshly cracked gives you those little bursts of spicy heat throughout
• 3 tablespoons olive oil: Helps the herb paste cling to the meat and promotes that gorgeous golden-brown exterior
• 1 lemon, zested and juiced: The brightness cuts through the rich lamb fat and keeps everything tasting fresh
• 1.5 kg (3.3 lb) Yukon Gold potatoes: These hold their shape beautifully while getting creamy inside and crisping up outside
• 2 tablespoons olive oil, 1 teaspoon kosher salt, ½ teaspoon black pepper, 2 teaspoons fresh rosemary, 4 cloves garlic smashed: Everything the potatoes need to become the most delicious part of the meal

Instructions

Preheat and prep:

Get your oven to 220°C (425°F) and grab your sharpest knife for the garlic incisions all over the lamb

Insert the garlic:

Push those sliced garlic cloves deep into the little cuts you made, distributing them evenly so every bite gets some of that mellow roasted flavor

Make the herb paste:

Mix rosemary, thyme, salt, pepper, olive oil, lemon zest and juice until it forms a fragrant paste that will coat the lamb beautifully

Season the meat:

Rub that herb mixture all over every surface, really working it into the meat so no spot is left bare

Let it rest:

Place the lamb in your roasting pan and let it sit at room temperature for about 30 minutes if time allows, which helps it cook more evenly

Prep the potatoes:

Toss your potato chunks with olive oil, salt, pepper, rosemary and smashed garlic until evenly coated

Arrange and roast:

Spread the potatoes around the lamb in the roasting pan and pop everything into the hot oven for 20 minutes to get things sizzling

Lower the heat:

Reduce temperature to 180°C (350°F) and continue roasting for about 1 hour 10 minutes, turning those potatoes halfway through for even browning

Check for doneness:

Insert your meat thermometer into the thickest part, looking for 60°C (140°F) for that perfect medium-rare that stays tender and pink

Rest the meat:

Transfer the lamb to a cutting board, tent loosely with foil, and let it rest for 15 to 20 minutes while you finish the potatoes

Crisp the potatoes:

Toss the potatoes in those precious pan juices and pop them back in the oven for a few minutes if they need extra crisping

Carve and serve:

Slice the lamb against the grain, arrange with those golden potatoes, and scatter fresh parsley over everything if you are feeling fancy

Save

My dad always says the sign of a good cook is how they handle the resting time, and he is absolutely right. That 20 minutes feels like forever when everyone is hovering around the kitchen, but it is what transforms a good roast into a great one. Plus it gives you a moment to breathe and pour yourself a glass of wine before the chaos of serving begins.

Getting The Right Doneness

I spent years overcooking lamb because I was terrified of undercooked meat, but a good thermometer changed everything. Medium-rare hits that sweet spot where the fat has rendered properly but the meat stays tender and juicy. If you have guests who prefer well-done, just slice their portions thinner and they can always put a piece back in the oven.

Potato Perfection Secrets

Yukon Golds are my absolute favorite for roasting because they have this natural butteriness that needs nothing else. The real trick is giving them enough room in the pan so they actually roast instead of steam, which is why I always use the largest roasting pan I own. overcrowding is the enemy of crispy edges.

Make It Your Own

Sometimes I throw whole garlic heads into the pan alongside the lamb, letting them roast until they spread like butter on crusty bread. Other times I add chunks of carrots or parsnips during the last hour of cooking. The basic formula works with whatever you have on hand, which is probably why I keep coming back to it.

• Try marinating the lamb overnight for even deeper flavor penetration
• A splash of wine in the pan during the last 30 minutes creates an instant pan sauce
• Leftover lamb makes incredible sandwiches the next day, especially with some of those roasted potatoes

Save

There is something deeply satisfying about putting a whole leg of lamb on the table, like you have accomplished something meaningful. The best moments always happen around a platter like this, with people reaching across the table and arguing over who gets the last crispy potato.

Recipe FAQs

→ What herbs enhance the flavor of the lamb?

Fresh rosemary and thyme are used to infuse the lamb with aromatic flavors, complementing the garlic and lemon zest.

→ How do I ensure the potatoes roast evenly?

Toss potatoes with olive oil, salt, pepper, rosemary, and garlic, then arrange them around the lamb to roast simultaneously for even crisping.

→ What internal temperature indicates medium-rare doneness?

The lamb should reach an internal temperature of 60°C (140°F) for a perfect medium-rare finish.

→ Can the lamb be marinated ahead of time?

Yes, marinating the leg of lamb overnight in the herb mixture enhances flavor and tenderness.

→ What side alternatives can be used with this dish?

Sweet potatoes, carrots, or parsnips can be swapped in or added to the roasting pan for variation and added sweetness.