Preheat a large skillet over medium heat while preparing the sandwiches.
Spread a thin layer of softened butter over one side of each slice of bread. Flip the bread over so the buttered side faces down.
Sprinkle half of the grated cheddar onto two slices of bread, creating an even layer that reaches close to the edges.
Arrange the tomato slices over the cheese and lightly season with black pepper if desired.
Drizzle about 1 teaspoon of Worcestershire sauce over each sandwich, making sure it lightly coats the tomatoes and cheese without soaking the bread.
Top with the remaining cheddar, then finish with the second slice of bread, keeping the buttered side facing outward.
Carefully transfer the sandwiches to the hot skillet. Cook slowly until the bottom is deeply golden and crisp while the cheese begins to melt.
Flip gently with a spatula and continue cooking until the second side is evenly browned and the cheese is completely melted. Reduce the heat slightly if the bread browns too quickly.
Let the sandwiches rest for a minute before slicing in half. Serve immediately while the cheese is perfectly gooey.