Combine first 4 ingredients in a bowl. Sprinkle feta evenly into a 6-inch gratin dish or small shallow baking dish coated with cooking spray. Top with tomato mixture. Bake at 350° for 20 minutes. Serve as a spread with bread slices.
This a fantastic appetizer, packed with flavor and super easy to make. I had extra feta on hand the first time I made it and ended up dicing some fresh tomatoes to supplement the canned, which added a really nice freshness. I agree that it is best consumed quickly, but it is amazing even after a short cooling period. I intend to strain it a bit and use it as a pizza sauce in the near future.