Grilled Potato Sandwich

Ingredients:

4 slices of white firm bread ( I am using buttermilk bread)
3 medium size potatoes boiled peeled and mashed, about 1-1/2 cups of mashed potatoes
2 tablespoon chopped cilantro (hara dhania)
1 teaspoon chopped ginger (adrak)
1 tablespoon chopped green chili (hari mirch)
½ teaspoon cumin seeds (jeera)
½ teaspoon salt
½ teaspoon mango power (amchoor)
2 tablespoons of melted butter
2 slices of cheddar cheese
8 tomato thinly sliced