Rinse long-grain basmati rice with water 2-3 times until the water runs clear. Soak the rice in 4 cups of water for 30 minutes.
Heat oil and ghee. Add asafoetida (hing), and 1 teaspoon cumin seeds and saute for 3-4 seconds.
Add cloves, whole black peppercorns, and black cardamoms and saute for 4-5 seconds.
Add chopped onions and fry till it turns slightly brown (5-6 minutes). Stir frequently while frying.
Add chopped tomatoes and fry for a minute.
Now add green peas, potatoes (peeled and cubed), and cauliflower (cut into small florets) and fry for 2-3 minutes. Stir frequently.
Add coriander powder, Kashmiri red chili powder, turmeric powder, garam masala powder, and salt and fry for another minute.
Drain the water from the rice and add the rice to the pressure cooker. Add water and stir gently.
Close the lid of the pressure cooker and pressure cook for 1 whistle on high heat.
TAHRI IS READY TO SERVE!