Stir together mayonnaise, mustard and cayenne pepper in a small bowl. Spread the mayonnaise mixture over all of the bread slices. Sprinkle half of the cheese over half of the bread slices. Top with turkey pastrami, black pepper, sauerkraut and the remaining cheese. Place the remaining bread slices firmly on top.Advertisement
Brush a little oil evenly over the bottom of a large nonstick skillet or griddle and heat over medium heat. Add the sandwiches in batches and cook until the undersides are lightly toasted and the cheese has melted, about 45 seconds per side. Add more oil to the pan as needed. Cut each sandwich into 2 triangles and serve warm.