Heat butter in a pan then fry the pastrami over low heat until lightly brown. Set aside
In the same pan, toast both sides of the 2 slices of bread.
Add the cheese on a slice of bread, then put the pastrami on the other slice of bread.
Place the slice of bread with cheese on the other slice of bread with pastrami. Transfer it on a plate, then slice it to two triangular pastrami sandwich.
Serve with parsley on the side and enjoy!