In a heavy saucepan over medium heat, warm the 1 tbsp vegetable oil. Add the chopped onion, garlic and ginger; sauté until golden and fragrant (about 3-4 minutes).
Add minced mutton to the pan, gently breaking lumps. Cook until the meat is no longer pink and moisture has mostly evaporated.
Add cumin powder, coriander powder, turmeric, chilli powder, ground cloves and ground cinnamon. Stir well so spices coat the meat. Cook 1-2 minutes.
Remove from heat and transfer mixture to a bowl. Let it cool slightly.
Add mashed potato, chopped coriander, mint, green chillies, garam masala, and salt. Mix thoroughly until well combined.
Stir in the breadcrumbs (or enough to make the mixture shapeable but not dry). If mixture is too loose, add more breadcrumbs a little at a time.
Divide mixture into 8 equal portions. Shape each into a cutlet (approx 7-8 cm diameter, 1.5 cm thick).
Place the beaten egg in one shallow bowl and extra breadcrumbs in another. Dip each cutlet first into egg, then coat with breadcrumbs, pressing gently to adhere.
Chill the coated cutlets in the fridge for 10 minutes (this helps them hold shape).
In a nonstick pan, heat oil to about 170–180 °C (enough to cover half the height of cutlet).
Fry cutlets 3–4 minutes each side until golden crisp and cooked through. Drain on paper towel.
Serve hot with mint-yoghurt dip, chutney, or wedge of lemon.
