Cheesy Skillet Chickpeas

Name: Cheesy Skillet Chickpeas
Prep time: 5 min
Cook time: 20 min
Total time: 25 min
Cuisine: Mediterranean
Ingredients: 1 tablespoon olive oil; 1 small onion, sliced into petals; 1 clove garlic, minced; 0.5 teaspoon Italian seasoning; 2 (15 ounce) cans chickpeas; 1 (24 ounce) jar chunky marinara sauce (such as Barilla®); salt and freshly ground black pepper to taste; 2 cups shredded mozzarella cheese; 1 (2.25 ounce) can sliced ripe olives, drained; 1 teaspoon chopped fresh oregano