Heat oil in a rice cooker, add bay leaves, cinnamon, black peppercorns, cloves, green cardamoms, cumin seeds and saute till fragrant.
Add onions and saute till soft. Add mushrooms, salt, turmeric powder, red chilli powder, garlic paste, ginger paste and mix well. Cover and cook.
Drain corn and add to the cooker, mix, cover and cook.
Separate mint leaves. Drain and add rice. Add mint leaves, 2½ cups water and mix well.
Add yogurt, saffron and garam masala powder and mix. Cover and cook till rice is done. Serve hot.