Over medium heat, add 1 tablespoon vegetable oil to a frying pan, then sauté the yellow onions until translucent.
Add the tomatoes to the onions, and continue to cook the vegetables for 5 minutes.
Remove the pan from the heat, and allow the onions and tomatoes to cool for 5 minutes.
Using a blender, the onions and tomatoes until the mix is smooth and paste-like.
In a pressure cooker (top off), heat 2 tablespoons of vegetable oil, then add in the bay leaves, cloves, fennel seeds, and cinnamon stick. Add the tomato/onion paste to the pressure cooker and cook the spices and paste for 2 to 3 minutes.
Add the ginger garlic paste to the mix, stir to combine, and cook for another 2 to 3 minutes.
Add the mutton to the pressure cooker and cook with the paste mix for 2 to 3 minutes.
Add the cayenne pepper powder, black pepper, ground turmeric, ground coriander, salt, and crushed curry leaves, along with 1/2 cup of water. Mix well to combine.
Bring the mix to a boil, then cover the pressure cooker. Cook the curry for 4 whistles or until the mutton is cooked and soft.
Transfer the curry into a sauté pan, then over medium heat cook off some of the sauce until you reach your desired consistency.
Once to your desired thickness, remove from heat and serve over rice. Garnish with coriander leaves.