Prepare sour cream by adding heavy cream, milk, lemon juice in a small bowl. Season a little bit of salt and whisk to mix everything well. Keep it aside.
Add small diced cucumber, capsicum, onion, and tomato (seeds removed) into a separate bowl. Continue to add boiled corns, all the seasonings. Add lemon juice, mayonnaise, mustard paste, and tomato ketchup. Mix everything well and keep aside.
Take a frying pan with a glass lid. Heat oil, add chicken mince, garlic paste. Add all the seasonings, the Sriracha, or Peri-Peri sauce. Stir fry for a while. Cook on low flame for 3 to 4 minutes with the lid on.
Take fresh bread slices as required and remove the crusts. Spread sour cream that you have already prepared. Arrange cooked chicken mince, layer with of cheddar cheese to taste. Carefully place the second layered bread slice and place the vegetable mayo you have already prepared and set aside. Cover with the third bread slice and spread some butter on the top.
Grease the sandwich maker with butter for around 2-3 minutes. Once done, cut the sandwiches diagonally and serve hot with your favorite sauce or chutney.