1. Preheat Oven & Prepare Onions
Preheat oven to 350°F (175°C).
Peel the onions and slice them into ¼-inch thick rounds. Separate the rings gently.
2. Layer the Onions & Butter
In a 9×13-inch baking dish, arrange the onion rings in an even layer.
Place thin pats of butter evenly over the onions.
3. Mix the Cheesy Sauce
In a medium bowl, combine mayonnaise, garlic powder, paprika, black pepper, salt, and thyme (if using).
Spread this mixture evenly over the onions.
4. Add the Cheeses
Sprinkle cheddar, mozzarella, and Parmesan cheeses evenly over the top.
5. Bake to Perfection
Bake uncovered for 40-45 minutes, or until the top is golden brown and bubbly.
If desired, broil for 1-2 minutes at the end for extra crispiness.
6. Garnish & Serve
Remove from oven and let rest for 5 minutes.
Garnish with fresh parsley before serving.
Nutrition Facts (Per Serving – Approx. ½ cup)
Calories Total Fat Carbs Protein
320 kcal 28g 10g 8g
Nutritional values are estimates and may vary based on ingredient brands.
Tips & Variations
