Preheat the oven 200℃/390℉. Line a baking tray with baking paper.
Pulse the oats, rosemary and 1 teaspoon garam masala in a food processor until it's the texture of fine breadcrumbs. Place on a plate.
Use a pastry brush to coat both sides of the cutlets with mint jelly. Press cutlets into the oat crumbs to coat. Place on a baking tray and cook for 10-15 minutes until lamb is cooked (if crumbs are not golden, finish off for 1 minute each side in a hot frying pan lightly sprayed with vegetable oil spray.)
Meanwhile, to make the spiced lentils, place a non-stick frying pan over a medium heat. Spray well with vegetable oil spray. Add onion and cook for 2-3 minutes. Add garam masala and cook for 1 minute. Add lentils and reduce heat to low. Cook for 2-3 minutes, until warmed through. Stir through lemon juice and parsley. Serve with the cutlets and salad.