Chop the slices of focaccia into bite-size pieces and keep them aside.
In a pan, add butter, garlic, and onion. Cook it till the onions turn pink. Add capsicum, tomato, red chili powder, pav bhaji masala, and salt. Once the vegetables are well-cooked and the masala is well combined, add a dash of water, and lemon juice, and mix well. Add the pieces of focaccia and mix well until all the pieces are coated in the masala. Top it with grated cheese and turn off the heat. Cover the pan and let the cheese melt.
Enjoy once slightly cooled!