French Onion Frittata
Recipe type: Breakfast
Prep time: 
Cook time: 
Total time: 
Serves: 8 servings
This frittata brings the flavor of a rich french onion soup to the breakfast table!
  • 2 Tbsp unsalted butter, divided
  • 2 cups day old bread, diced into 1” cubes
  • 1 Tbsp extra virgin olive oil
  • 2 large yellow onions, thinly sliced
  • 1.5 tsp kosher salt, divided
  • 1 Tbsp balsamic vinegar
  • 8 large eggs
  • ¼ cup whole milk
  • 1 Tbsp Dijon mustard
  • ¼ tsp black pepper
  • ½ cup (2 ounces) Gruyere cheese, shredded
  • 1 Tbsp fresh chives, thinly sliced
  1. Preheat the oven to 400°F.
  2. Heat a 10-inch cast iron skillet over medium heat. Add 1 Tbsp of butter and melt. Add the cubed bread to the pan and toss to coat with butter. Toast the bread cubes, tossing every few minutes, until all sides are golden and crispy. Once done, transfer the bread to a bowl and set aside.
  3. Reduce heat to low. Add the olive oil, onions, and ½ tsp salt to the skillet. Cook, stirring every 5-10 minutes, until the onions are soft and deep brown (about 40 minutes total). Add the vinegar and scrape the browned bits off the bottom of the pan.
  4. In a large bowl, whisk together the eggs. Add the milk, mustard, remaining 1 tsp salt, and pepper, and whisk to combine.
  5. In the skillet, add the remaining 1 Tbsp butter. Add the bread back to the pan, spreading into one even layer. Pour the egg mixture over top. Top with the shredded gruyere. Cook until the eggs around the edge of the pan begin to set (about 2-4 minutes).
  6. Remove from the heat and move to the preheated oven, cooking for 10-15 minutes, or until the eggs are fully set.
  7. Remove from oven and cool for 5 minutes. Top with fresh chives, slice and serve hot.
Recipe by hOhm Cooking at