Baked Gnocchi Casserole in Creamy Tomato Sauce

Bahan-bahan (5 porsi)

• 1 ½ pounds gnocchi (store bought)
• 1 tablespoon olive oil
• 2 cloves garlic (minced)
• ½ onion (finely chopped)
• 24 ounces marinara sauce
• ½ cup heavy whipping cream
• 1 teaspoon Italian seasoning ((optional))
• 1 cup shredded mozzarella cheese
• ½ cup basil leaves (torn or chopped)