Preheat oven to 350°F. Slice French bread in half lengthwise and scoop out some of the center bread. Brush bread rounds on both sides lightly with oil, place on baking sheet. Bake until beginning to crisp, 10-15 minutes. Cool 5 minutes.
Top each bread round with half of cheeses, oregano, and crushed red pepper. Sprinkle each with half of tomatoes and olives. Bake bread rounds until cheeses melt and bottoms are crisp, about 15 minutes. Cut into slices.