Fugazzeta: Stuffed Argentinian-Style Pizza

Name: Fugazzeta: Stuffed Argentinian-Style Pizza
Prep time: 1 h 30 min
Cook time: 35 min
Total time: 2 h 5 min
Cuisine: Latin American
Ingredients: 1/4 cup milk; 2 teaspoons sugar; 2 1/2 teaspoons active dry yeast; 2 3/4 cups bread flour; 5 tablespoons olive oil, divided; 1 teaspoon salt; 3/4 cup water; 1 onion; 6 to 8 ounces mozzarella cheese (thinly sliced); Optional: 1/3 cup aged provolone cheese (grated); 1 teaspoon dried oregano; 1/4 cup Parmesan cheese (grated)