Prosciutto Potato Bake

Name: Prosciutto Potato Bake
Ingredients: 2 tablespoons olive oil, divided; 0.5 pound sliced prosciutto, or more to taste; 0.5 pound small potatoes, sliced thinly lengthwise; 2 tomatoes, sliced; 1 (4 ounce) ball fresh mozzarella cheese, thinly sliced; 0.5 (6 ounce) jar sliced mushrooms, drained; 0.25 teaspoon salt; 0.25 teaspoon ground black pepper; 0.25 teaspoon dried oregano; 0.25 teaspoon garlic powder; 0.25 teaspoon finely chopped green onion