Preheat broiler and set oven rack one notch down from the broiler. In a bowl, combine all ingredients besides the bread and tomatoes. Stir to combine. On a baking sheet lined with aluminum foil, place bread slices in a single layer and lightly toast under the broiler, 20-30 seconds. Remove toast from the broiler, flip slices over and evenly cover with cheese mixture. Place pan back under broiler, and cook until cheese is bubbling and golden, approximately 2 minutes. Place tomato slices on bread, season with salt and pepper and serve.