Put finely chopped onion and capsicum into beef mince and add pepper and salt as much you desire and mix it with hands.
Add butter and bread crumbs and carry on mixing. Make small patties from the mince.
Fry the patties in oil.
When the patties are almost ready put cheese, onion and tomato ketchup on each Pattie.
Cut the buns from center and then slice them in two or three pieces (optional)
Pour some ketchup and mayonnaise on each side (as much you desire)
Put one Pattie in the center of every bun’s piece.
You can take buns of your choice in round or flat shape.
Burger is ready to serve.