Oven-Roasted Lamb with Rosemary and Mint Sauce

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · ·

Tender roasted lamb leg infused with fresh rosemary, paired with a vibrant mint sauce for a classic British flavor combination. This british-inspired lamb ready in about 100 minutes pairs bone-in leg of lamb, fresh rosemary sprigs, garlic cloves, minced for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 480 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart.

Prep: 20 min Cook: 80 min Serves 6 British cuisine 480 cal/serving
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Ingredients

Instructions

  1. Step 1: Preheat oven to 375°F. In a small bowl, combine 3 tbsp olive oil, 4 minced garlic cloves, 2 tsp salt, 1 tsp black pepper, and finely chopped leaves from 4 fresh rosemary sprigs. Rub this mixture all over the 4 lbs bone-in leg of lamb, coating evenly.
  2. Step 2: Place the lamb on a roasting rack in a roasting pan and roast in the oven for 1 hour and 20 minutes, or until an internal temperature of 135°F for medium-rare is reached, basting occasionally with pan juices.
  3. Step 3: While the lamb rests, prepare the mint sauce by finely chopping 1 cup fresh mint leaves and combining with 3 tbsp white wine vinegar, 1 tbsp granulated sugar, and 1/4 cup water in a bowl. Stir until sugar dissolves and let it sit to meld flavors.
  4. Step 4: Slice the rested lamb and serve with a generous drizzle of the mint sauce on top, offering a refreshing contrast to the rich meat.

Frequently asked questions

How long does Oven-Roasted Lamb with Rosemary and Mint Sauce take to make?

Total time is about 100 minutes (20 min prep + 80 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Oven-Roasted Lamb with Rosemary and Mint Sauce?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep bone-in leg of lamb from drying out.

Can I substitute ingredients in Oven-Roasted Lamb with Rosemary and Mint Sauce?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Oven-Roasted Lamb with Rosemary and Mint Sauce for a different number of people?

The recipe is written for 6 servings. Multiply each ingredient by (your serving target / 6). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

What goes well with Oven-Roasted Lamb with Rosemary and Mint Sauce?

British lamb like this pair well with a simple grain (rice, couscous, or crusty bread), a quick salad with acid (lemon vinaigrette, pickled onions), and a pan sauce or yogurt-based dip. Tap "Plan a meal with the AI" to get specific side suggestions.

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