Butter each side of bread. Place four slices of bread butter side down in the pan. Add a layer of smoked cheddar cheese to cover the bread. Place approximately ¼ cup of shredded brisket on each slice of the bread, then layer with gruyere cheese. I like to cover with a lid while the cheese is melting. Once the cheese is melted on the bottom and you can see it melting on top, add the other slice of bread, butter side up and carefully flip the sandwiches. Press each lightly and continue to cook until the cheese is melted and the bread is golden brown. Cool slightly before cutting.