Preheat oven to 300 degrees. Slice bread into 1/4-1/2 inch thick slices. Brush lightly with olive oil. Place slices on an ungreased cookie sheet and toast for 10 minutes, removing and flipping the slices over halfway through. (Each oven is different, but you want to toast until the bread is crispy, but not browned. Don't let it burn!)
Chop tomatoes into small pieces, removing cores and stems. Drain excess juice from chopped tomatoes by gently pressing them in a colander. Transfer to a clean bowl, and toss tomatoes with salt, pepper, oregano, basil, and feta.
Let bread cool until it's safe to touch. Rub bread with peeled garlic cloves. The dry bread should cause the garlic break down and smear onto the bread, flavoring it. Increase oven heat to 350
Put bread back on cookie sheet and top with spoonfuls of the tomato mixture. Return to oven and toast at 350 degrees for 5-10 minutes, until tomatoes start to wilt and cheese starts to melt. Remove and serve immediately. (Depending on the size of your bread and tomatoes, it will make a lot!) Enjoy!