Onions Au Gratin

Onions Au Gratin


"This cheesy onion side dish is a household favorite at Thanksgiving dinner."

Ingredients 30 m {{adjustedServings}} servings 228 cals

Serving size has been adjusted!

Original recipe yields 8 servings



Amount per serving ({{servings}} total)

  • Calories:
  • 228 kcal
  • 11%
  • Fat:
  • 17.4 g
  • 27%
  • Carbs:
  • 10.7g
  • 3%
  • Protein:
  • 8.2 g
  • 16%
  • Cholesterol:
  • 55 mg
  • 18%
  • Sodium:
  • 297 mg
  • 12%

Based on a 2,000 calorie diet

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  • Cook

  • Ready In

  1. Preheat the oven to 350 degrees F (175 degrees C). Grease an 8 inch square baking dish.
  2. Melt the butter in a large skillet over medium heat. Add onions; cook and stir until tender, about 5 minutes. Transfer to the prepared baking dish. In a medium bowl, stir together the beef broth and flour until smooth. Mix in the cream and season with salt and pepper; pour over the onions. Sprinkle Swiss cheese and Parmesan cheese over the top.
  3. Bake for 25 to 30 minutes in the preheated oven, until cheese is golden brown and the sauce is bubbly.
Tips & Tricks
Potato and Parsnip Gratin

A rich gratin with potatoes, parsnips, and Parmesan cheese.

Pancetta-Wrapped Leek Gratin

Leeks are wrapped in pancetta, topped with Parmesan and cream, and baked.

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Reviews 15

  1. 17 Ratings


this is an absolute wonderful recipe. if you like onions this is the recipe to try, don't change anything.


I really wanted this recipe to be great - but it was a disaster! I should have known something would go wrong since onions give off a lot of water/juices when they cook! The end result was NOT a traditional "au gratin" dish but more of cheesy soupy onion mess. It was hardly edible and a great disappointment (not to mention waste of perfectly good onions)! My only recommendation/suggestion for fixing this would be to bake the onions first without the mixture - pour off the excess liquid - then add the flour/cream mixture and cheeses and bake again... that's the only thing that comes to mind to avoid the soup I ended up with. However, with that said - I will NOT be making this again!

Sarah Jo

This is absolutely one of my most favorite sides. I suggest, if you can find them in your area, using the sweets. And using Campbell's double strength beef broth really amps up the flavor, you'll just have to cut out the excess salt. And a little more cheese never hurt anyone. ;)