From chef-owner Suzanne Goin. She recommends serving the sandwich with an arugula salad dressed with lemon juice and best-quality olive oil.
2 large shallots
3 tablespoons unsalted butter, divided
1/2 teaspoon thyme leaves
2 slices country white bread, sliced 1/2 -inch thick
5 ounces Cantal cheese, sliced 1/8-inch thick