Rinse potatoes and place in an ovenproof dish. Drizzle with 2 tablespoons olive oil and season with salt. Cover and roast in an oven preheated to 200°C (approximately 400°F) for 50 minutes.
Rinse basil, shake dry and pluck off leaves.
Mince half of the basil leaves and mix with lemon zest and ricotta. Season with salt and pepper.
Spread ricotta onto lamb, roll up and secure with a toothpick.
Blanch tomatoes, shock in ice water, peel, core and quarter.
Peel and slice onions.
Grease an ovenproof dish with 1 tablespoon olive oil. Add tomatoes, lamb cutlets and onion. Cover with white wine. Drizzle lamb with remaining olive oil. Season with salt and pepper and roast for 30 minutes.
Remove and plate with potatoes. Serve garnished with remaining basil leaves.