Heat olive oil in a large skillet over medium heat. Add onion and bell peppers and cook for 5 minutes, stirring occasionally.
Add garlic, oregano and basil. Cook for an additional 2 minutes.
Season with salt and pepper to taste.
Spread 1 tablespoon of olive oil on one side of each slice of bread. Place two slices of bread in the skillet, oil side down. Top each slice with a slice of cheese and the cooked vegetables.
Top with remaining two slices of bread, oil side up. Cook until golden brown on each side.