Preheat the oven to broil. Line a small rimmed baking sheet with aluminum foil.
In a small bowl, combine the cracker crumbs, blue cheese, bacon, and green onions. Add the melted butter, stirring to mix well.
Place the tomatoes, cut sides up, on the prepared baking sheet. Sprinkle the tomato halves evenly with the salt and pepper. Divide the cracker mixture evenly among the tomato halves. Broil 5 inches from the heat with the oven door cracked open until lightly browned, 5 to 7 minutes.
Cook's Note: Use cherry tomatoes to make cute lil' appetizers!