1.Mix all the cheese in a bowl.
2.Spread the butter on one side of the bread slices.
3.Place a pan on low heat.
4.Place a slice, butter it down, and add cheese mix with cooked bacon.
5.Spread the mustard on the unbuttered side of the slice and place it over the bacon.
6.Heat the bread gently until it forms a golden crust. This could take 3 to 4 minutes.
7.Carefully flip the sandwich with the help of a spatula. Cook until a golden crust is formed.
8.Repeat to make four sandwiches.
9.Cut and serve immediately.