Oven-Roasted Lamb with Rosemary and Mint Sauce

By AislePrompt Editorial · Published 2026-05-08 · Updated 2026-05-08

How this recipe was made — this recipe was drafted by AislePrompt's AI-assisted pipeline from technique templates and USDA-sourced nutrition data, and published by AislePrompt Editorial — see how AislePrompt recipes are developed and reviewed.

Tender roasted lamb leg infused with fresh rosemary, paired with a vibrant mint sauce for a classic British flavor combination. This British-inspired lamb recipe, 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. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

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

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Ingredients

4 lbs bone-in leg of lamb
4 fresh rosemary sprigs
4 garlic cloves, minced
3 tbsp olive oil
2 tsp salt
1 tsp black pepper
1 cup fresh mint leaves
3 tbsp white wine vinegar
1 tbsp granulated sugar
1/4 cup water

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Instructions

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.
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.
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.
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.