Finely chop the onion, capsicum, tomato, and fresh coriander. Grate the cheese if using a block.

Heat 1 tbsp butter in a pan over medium heat. Add 1 cup onion and sauté until soft and lightly golden, about 3 to 4 minutes.

Add 1/2 cup capsicum and 1/2 cup tomato to the pan. Cook until the tomato softens and the mixture becomes saucy, about 4 to 5 minutes.

Stir in 1.5 tsp garlic chutney, 1 tbsp pav bhaji masala, 1 tsp chilly powder, 1 tsp ground cumin, and salt. Cook the masala for 2 minutes, stirring continuously.

Stir 1 tbsp fresh coriander into the cooked masala. Transfer the filling to a bowl and keep warm.

Split 4 pav rolls horizontally without cutting fully through. Spread a little butter on the cut sides of each pav roll.

Toast the buttered pav rolls cut-side down in the pan until golden and crisp. Turn them once to warm the outer sides.

Spoon the warm masala filling inside each toasted pav roll. Spread a little filling over the outside of each roll.

Top the masala pav with cheese, onion, and remaining fresh coriander. Finish with lemon juice and serve with green chutney.