Heat a nonstick frying pan or griddle until hot, add the cutlets and cook for 1 minute on each side, then transfer to a baking sheet.
Mix together the pesto, breadcrumbs and walnuts and use to top one side of the cutlets, pressing down lightly. Cook in a preheated oven, 200°C (400°F), Gas Mark 6, for 10–12 minutes.
Meanwhile, heat the oil in a frying pan or wok, add the garlic and stir-fry for 1 minute, then add the greens and continue to stir-fry for 3–4 minutes until tender.
Serve the lamb and greens along with some baby carrots.