Preheat oven to 375.

Coat large shallow baking dish with cooking spray. Cut peppers in half lengthwise, remove seeds, but leave stem. Place cut side up in dish.

Divide sliced garlic and olives evenly among peppers. Cut each tomato in 8 wedges each and put 4 wedges in each pepper half. Drizzle each half with a little oil and season with freshly ground pepper.

Roast peppers until tender, beginning to brown around edges - about 50 minutes. Serve immediately.