3 large sweet onions, sliced into 1/4-inch slices
1 1/2 teaspoons Cajun seasoning, or more to taste
1 teaspoon garlic powder
4 tablespoons butter, cut into 6 slices
1 cup shredded cheddar cheese
1 cup shredded mozzarella cheese
1/2 teaspoon dried oregano
1/2 cup grated Parmesan cheese
Step 1
Preheat the oven to 175 degrees Celsius (350 degrees Fahrenheit).
Step 2
Layer half of the sliced onions on the bottom of a 23x33cm casserole dish. Sprinkle with half of the Cajun seasoning and half of the garlic powder. Repeat with the remaining onions, seasoning, and garlic powder.
Step 3
Arrange the butter slices on top of the onions and evenly distribute the Cheddar and mozzarella cheese over them. Sprinkle the oregano over the cheese and finish with a layer of Parmesan cheese.
Step 4
Bake in the preheated oven until the onions are tender and the cheese is melted, bubbly, and golden brown around the edges, about 35 minutes.