Step 1 Brush both sides of lamb cutlets with pesto and set aside. Blanch beans and peas until tender-crisp. Drain and set aside.
Step 2 Spray a large frying pan with oil and place over medium heat. Add onion and cook, stirring occasionally, for 5 minutes, until soft. Add garlic and cook, stirring, for 1 minute. Add tomatoes and cook, stirring occasionally, for 3–4 minutes. Add capsicum and zucchini. Cook for 2–3 minutes, until zucchini is just tender. Add blanched beans and peas, and cook for 1 more minute. Remove from heat, stir through oregano and keep warm.
Step 3 Meanwhile, steam sweet potato, then mash.
Step 4 Spray another frying pan with oil and place over high heat. Cook cutlets for 2 minutes each side for medium, or until cooked to your liking. Serve ratatouille with lamb cutlets and sweet potato mash.