Once the oil is hot, add cloves, black peppercorns, green cardamoms, and black cardamom to it and fry for 4-5 seconds.
Add onions and cook until they turn translucent (4-5 minutes), stirring frequently.
Add ginger garlic paste and cook until the onions turn golden brown (6-8 minutes).
Add tomato, yogurt, and green chilies and cook for 2-3 minutes.
Add coriander powder, Kashmiri red chilli powder, turmeric powder, garam masala powder, black pepper powder, and salt, and cook until the oil starts to separate from the sides.
Add the mushrooms and bell pepper (cut into small cubes) and mix well.
Reduce the heat to medium-low.
Cover the pan and cook the curry for 18-20 minutes, stirring occasionally.
If the curry gets dry while cooking, then add some water to it.