Add the mutton, garlic, ginger, turmeric powder, chili powder, salt, and water to a pressure cooker. Pressure cook for about 15 minutes or until the mutton becomes tender. Reserve about 1 cup of the cooking liquid and set aside.
Heat oil in a large pan over medium heat. Add the dried red chili, curry leaves, fennel seeds, cumin seeds, and mustard seeds. Allow them to sizzle until fragrant.
Add the diced onion and sauté until lightly golden. Stir in the pandan leaf, cardamom pods, cinnamon stick, and cloves. Add the diced tomato and sliced green chilies. Cook until the tomatoes soften.
Stir in the cumin powder, coriander powder, black pepper, and garam masala. Cook the spice mixture for 1-2 minutes.
Add the cooked mutton along with 1 cup of the reserved broth.
Cook uncovered, stirring occasionally, until most of the liquid evaporates.
Continue cooking until the curry becomes thick, dry, and coated in spices.
Garnish with fresh coriander leaves before serving.
Serve hot with rice, chapati, parotta, or roti.