Tennessee Onion Casserole


  • 2 1/2 lbs. Sweet onions (sliced into 1/4" slices and rings separated)
  • 1 tsp Dried thyme
  • 1 tsp Dried parsley flakes
  • 1 tsp Garlic salt
  • 1/2 tsp Dried oregano
  • 1/2 tsp Dry mustard
  • 1/4 tsp Cayenne pepper
  • 1/4 cup salted butter (cut into 1/4 in. pieces
  • 1 cup Shredded mild Cheddar cheese
  • 1 cup shredded smoked Gouda cheese


  • Preheat oven to 350 degrees Fahrenheit. Coat a 13 x 9 inch baking dish with cooking spray. Gather your ingredients.
  • Place onions in a large bowl. Sprinkle with thyme, parsley, garlic salt, oregano, mustard, and cayenne pepper; toss gently to coat. Arrange evenly in prepared baking dish.
  • Arrange butter evenly over onions, and sprinkle with Cheddar and Gouda. Cover with aluminum foil, and bake in a preheated oven until onions are soft and sides are bubbly about 40 minutes.
  • Remove foil. Bake at 350 degrees Fahrenheit until top is golden, about 30 minutes.