Onions Au Gratin (Onion Casserole)

Onions au Gratin (Onion Casserole)

Alex's illustration of her Onions au Gratin recipe.

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  • 4 Packed Cups (About 5 Medium) Yellow Onions
  • 1/2 tsp Salt
  • 1 Cup Boiling Water
  • 2 tbsp Organic Meadow Salted Butter
  • 2 tbsp *Flour
  • 1/2 tsp Salt
  • 1 Shake Pepper
  • 1/4 Cup Reserved Onion Cooking Liquid
  • 1 Cup Organic Meadow 3.8% Milk
  • 1 Cup Grated Organic Meadow Old Cheddar Cheese
  • 3 Slices *Bread
  • 1/4 Cup Melted Organic Meadow Salted Butter


Preheat your oven to 375 degrees. Peel your Onions, and cut into 1/2 inch thick slices. 4 Cups should be about 5 medium-sized Onions—but if you’re an Onion fan, feel free to err to the side of more Onions, rather than less! 

Put the onions, water and salt into a large and deep non-stick pan with a lid. Bring the Water with the Onions and Salt to a boil. Cover and cook for 10 minutes. The Onions should be a little limp, but not mushy. Drain the liquid, but reserve a 1/4 Cup for the Sauce. Arrange the slices in a greased 9 x 9 pan, separating out the rings. This will help the Sauce to evenly distribute itself when you pour it into the pan.


In a small sauce pan, melt your Butter. When the Butter is melted, add in the *Flour, Salt and Pepper. Whisk together, and then add the reserved Onion Cooking Liquid and the Milk. Stir this mixture until it thickens. Remove the mix from the heat, and then stir in the Cheese until it melts. Pour the Sauce over the Onions. With a spoon or fork, help the Sauce to flow down between the separated Onions.


Cut the *Bread into cubes and toss in the melted Butter to lightly coat. Arrange the cubes on top of the Onions and Sauce in the pan.

Bake uncovered at 375 degrees for 25 to 30 minutes.

Serve and enjoy!

Be sure to visit Alex's Blog and Website for more fantastic illustrations and recipes!

*For a Gluten-free version of this recipe, click here.

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