Peel and clean onion and slice it and keep aside.
Take tomatoes and make puree and keep aside.
Make Julian from red capsicum, green capsicum and Tomato.
Slice paneer and keep aside.
Heat oil in a pan, add kalonji and zeera to it. Let it crackle and then add sliced onion and fry upto pink in color. Add ginger and garlic paste and fry in high flame for 3mins. Then add Tomato puree and lower the flame and sauté again. Add all dry masalas, salt,and sugar except garam masala. sauté upto masala separates from oil.
Add veggies Julians and 1/4 cup of water to it. Let the veggies cook. Now add paneer to it and toss it with the masala and cover and cook for 5mins.
Now add garam masala and chopped coriander leaves and switch off the gas.
Serve hot with roti, paratha or nan