Heat oil in a pan on medium heat. Once oil is hot, add cloves and peppercorn. Saute for few seconds till fragrant and then add cumin seeds and mustard seeds. Wait till cumin seeds sizzle and mustard seeds start popping out. Add chopped onions now and cook for 2-3 minutes or till they start turning light brown in color. Add garlic, ginger and green chili and mix.
To make pav bhaji, specifically the bhaji – onion, ginger-garlic paste, tomatoes, are sauteed in butter first. Later to which boiled and mashed vegetables are added followed by pav bhaji masala. Then the bhaji is simmered for some minutes later to be served hot with buttered and lightly toasted pav. Pav are Indian bread rolls. In the streets and in restaurants, pav bhaji is made on a large flat tawa (griddle). At home you can make pav bhaji in a kadai or in a frying pan. Pav bhaji has a bright orangish red color. When you make pav bhaji at home, you won’t get the color that you typically see in hotels and restaurants. Some street vendors also add artificial red color. As far as possible avoid the use of artificial food colors and use natural colors instead. So to get the red color in pav bhaji, use Kashmiri red chilli powder or deghi mirch. Alternatively you can even make red chili paste. Soak 2 to 3 Kashmiri red chilies (seeds removed) in hot water for 30 minutes, then make a fine paste and add to the pav bhaji.