Ratatouille Sandwich
1 clove garlic, minced 1 eggplant, sliced 1 red bell pepper, sliced 1 red onion, sliced 1 teaspoon dried oregano, or to taste 1 tomato, chopped 1 tomato, sliced 1 zucchini, sliced 4 slices mozzarella cheese 4 slices sourdough bread 4 teaspoons olive oil salt and ground black pepper to taste