Halve the tomatoes horizontally and trim the ends so that they will stand level, cut side up. Brush them all over with the oil and bake them, cut side up, on a baking sheet in the middle of a preheated 325 degree oven for 20 minutes.
In a small bowl combine the remaining ingredients with salt and pepper to taste and divide the mixture among the tomatoes. Drizzle oil over the tomatoes and broil them under a preheated broiler about 4 inches from the heat for 2 to 3 minutes, or until the topping is golden brown.