Prepare the vegetables and bread: Wash and slice all the vegetables thinly. Boil and slice the potatoes.
Spread butter and green chutney on one side of three bread slices, then set them aside.
Assemble the sandwich:Place a slice of bread, buttered side up, on a clean surface.
Spread a layer of green chutney on the bread.
Layer the sliced vegetables in the following order: potato, and onions on the bread slice.
Add a sprinkling of sandwich masala over the vegetable layers.
Top this with another slice of bread, ensuring the buttered and chutney-coated side is facing downward.
On the upper side of this new bread slice, spread both chutney and butter.
Add layers of tomato and cucumber, then sprinkle sandwich masala over these vegetables.
Distribute cheese evenly on top of the vegetable layers.
Finish by placing a third slice of bread on top, with its buttered and chutney-spread side facing down.
Grill the sandwich:Heat a sandwich grill or a flat pan over medium heat.
Place the assembled sandwich on the grill or pan.
Cook for 2-3 minutes on each side, or until the bread turns golden brown and crispy.
Serve: Cut the grilled Bombay Sandwich diagonally and serve hot with additional chutney on the side.