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Cheesy Onion Casserole Recipe

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★★★★★

5 from 73 reviews

This Cheesy Onion Casserole is a rich and comforting dish featuring sweet onions softened in butter and olive oil, combined with a creamy blend of cheese, mayonnaise, and mushroom soup, then baked to golden perfection. Perfect as a savory side or a hearty addition to any meal.

Ingredients

Scale

Onions and Fat

  • 3 lbs. Sweet Onions, sliced into 1/4 to 1/2 inch half moons
  • 2 tablespoons Butter
  • 2 tablespoons Olive Oil

Cheese Mixture

  • 4 cups Shredded Cheese (cheddar or a blend works well)
  • 1 cup Mayonnaise
  • 1 can Cream of Mushroom Soup (approx. 10.5 oz)
  • 1/2 can Milk (use the same soup can for measurement)

Seasonings

  • 1 teaspoon Parsley
  • 1 teaspoon Chives
  • 1/2 teaspoon Thyme
  • 1 teaspoon Garlic Powder
  • 1 teaspoon Onion Powder
  • 1/2 teaspoon Kosher Salt
  • 1/2 teaspoon Black Pepper

Instructions

  1. Prepare Onions: Peel and slice your sweet onions into 1/4 to 1/2 inch half moons, ensuring even thickness for uniform cooking.
  2. Heat Fat: In a large skillet over medium heat, melt 2 tablespoons of butter and 2 tablespoons of olive oil together until the butter becomes foamy.
  3. Cook Onions: Add the sliced onions to the skillet and stir to coat them evenly in the butter and oil mixture.
  4. Soften Onions: Cover the skillet and let the onions soften over medium heat for 10 to 15 minutes, stirring occasionally to prevent sticking or burning.
  5. Mix Cheese Base: In a large mixing bowl, combine 4 cups shredded cheese, 1 cup mayonnaise, 1 can of cream of mushroom soup, and half a can of milk. Stir thoroughly to create a creamy mixture.
  6. Add Seasonings: Incorporate 1 teaspoon parsley, 1 teaspoon chives, 1/2 teaspoon thyme, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1/2 teaspoon kosher salt, and 1/2 teaspoon black pepper into the cheese mixture. Mix well to evenly distribute the flavors.
  7. Combine Onions and Cheese Mixture: Once the onions are soft and fragrant, pour them into the cheese and soup mixture. Stir until all ingredients are thoroughly combined.
  8. Prepare and Bake: Butter a 9×13-inch casserole dish and pour in the combined mixture, spreading it evenly. Bake in a preheated oven at 350°F (175°C) for 30 to 35 minutes, or until the top is golden brown and bubbly. Allow to cool slightly before serving.

Notes

  • For best results, use sweet onions such as Vidalia or Walla Walla for a naturally sweeter flavor.
  • You can substitute the cream of mushroom soup with cream of chicken or celery soup if preferred.
  • Feel free to use a blend of cheeses like cheddar and Monterey Jack for added flavor complexity.
  • This casserole can be prepared ahead of time and refrigerated before baking; increase baking time slightly if baking from cold.
  • Leftovers can be stored covered in the refrigerator for up to 3 days and reheated in the oven for best texture.

Keywords: Cheesy Onion Casserole, onion casserole, baked onion dish, cheesy side dish, comfort food casserole

Find it online: https://tastybynova.com/cheesy-onion-casserole-recipe/