
Preheat the oven to 400°F and grease a baking tray with oil.
Toss the green beans with olive oil, garlic, salt, and pepper until well coated.
Spread the green beans evenly on the prepared baking tray.
In a small bowl, mix together the Parmesan and mozzarella cheese.
Sprinkle the cheese mixture over the green beans and bake for 20 minutes, until the cheese is melted and golden.
Once done, let the beans rest for 10 minutes before serving.