Herb-Roasted British Lamb with Minted Pea Purée

By AislePrompt Editorial · Published 2026-05-10 · Updated 2026-05-10

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 drafted and published.

Tender British lamb roasted with fresh herbs, served alongside a vibrant minted pea purée — a classic British Sunday roast centrepiece. This British-inspired lamb recipe, ready in about 95 minutes, pairs British lamb leg, fresh rosemary, fresh thyme for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 450 calories and feeds 4, 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: 75 min Serves 4 British cuisine 450 cal/serving

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Ingredients

2 lbs British lamb leg
2 tbsp, chopped fresh rosemary
1 tbsp, chopped fresh thyme
4, minced garlic cloves
3 tbsp olive oil
1 tsp sea salt
1/2 tsp black pepper
2 cups frozen peas
1/4 cup, chopped fresh mint leaves
2 tbsp unsalted butter
1 tbsp lemon juice

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Instructions

Step 1: Preheat oven to 375°F. Combine 3 tbsp olive oil, 2 tbsp chopped rosemary, 1 tbsp chopped thyme, 4 minced garlic cloves, 1 tsp sea salt, and 1/2 tsp black pepper in a small bowl. Rub this herb mixture all over the 2 lbs British lamb leg.
Step 2: Place the lamb on a roasting rack in a baking pan and roast for 1 hour 15 minutes or until the internal temperature reaches 135°F for medium-rare. Remove from oven and let rest for 15 minutes.
Step 3: While the lamb roasts, bring a saucepan of salted water to a boil. Add 2 cups frozen peas and cook for 3 minutes until tender and bright green. Drain and transfer peas to a blender.
Step 4: Add 1/4 cup chopped fresh mint leaves, 2 tbsp unsalted butter, and 1 tbsp lemon juice to the peas. Blend until smooth and season with salt and pepper to taste.
Step 5: Slice the rested lamb and serve with a generous dollop of minted pea purée on the side.