Debone mutton leg and beat with hammer. Apply papaya paste and leave for 1 hour.
In a bowl combine lemon juice, ginger garlic paste, green chilies, red chili, black pepper, garam masala, salt and oil.
Coat mutton leg with this marination and leave for 4-6 hours.
Then put mutton leg on aluminum foil, top with onion, tomato, and capsicum and wrap carefully.
Bake in preheated oven at 180 C for 40-50 minutes or until fully tender.
Set in serving platter garnish with lemon wedges and sliced onion and serve.