Apply some butter on both sides or bread slices. Arrange on an oven mesh-tray.
Apply some ketchup mixture on each. Leave sauce behind to top. Arrange first salad leaves, then onion, potato, tomato capsicum and cucumber. Top with thin slivers of cheese finally dot with ketchup mixture.
Preheat oven to 300 degree Celsius.
Grill the sandwiches till the bread get toasted and cheese melts well. Cut into triangles with pizza cutter serve hot.