Heat butter in a pan and add onions and garlic paste. Sauté for 2 minutes. Add capsicum and sauté for another minute.
Add finely chopped tomatoes and Rainbow Pav Bhaji Masala and sauté till the butter separates from the masala.
Add boiled mashed mixed vegetables, salt and chilli powder to taste and simmer for 10 minutes.
Garnish the bhaji with chopped coriander, onions and some butter. Serve hot with buttered pav.