Skip to main content
LoginSign Up
Onion Frittata with Sherry Vinegar Sauce

Onion Frittata with Sherry Vinegar Sauce

  • Makes
    4 servings
  • Cook Time
    25 minutes
  • Rating

The sautéed onion makes this frittata sweet and succulent, while the butter-vinegar sauce and fresh chives elevate what too often is a dish with humble flavors. If you like, you can use red wine vinegar in place of the sherry vinegar and shredded Gruyère cheese instead of Parmesan. A pile of simply dressed greens goes great with this frittata.

Tip

Don't omit the cheese. It adds a savory element that balances the sweetness of the onions. Also, don't use a conventional skillet. Nonstick is essential so that the frittata slides out of the pan with ease.

Ingredients
  • 8

    large eggs

  • Kosher salt and ground black pepper

  • 4

    tablespoons salted butter, cut into 4 pieces, divided

  • 1

    medium yellow onion, chopped (about 1 cup)

  • 1

    medium garlic clove, grated

  • ¼

    cup plus 1 teaspoon sherry vinegar

  • ½

    cup grated Parmesan cheese

  • 1

    tablespoon whole-grain mustard

  • 4

    tablespoons minced fresh chives, divided

Step 1

Heat the oven to 325°F with a rack in the upper-middle position. In a large bowl, beat the eggs with ¾ teaspoon salt and ½ teaspoon pepper.

Step 2

In a 10-inch ovenproof nonstick skillet over medium-low, melt 1 tablespoon of the butter. Add the onion and ½ teaspoon salt, cover and cook, stirring occasionally, until softened and moisture is released, about 5 minutes.

Uncover, increase the heat to medium-high and cook, stirring occasionally, until well browned, about 10 minutes. Stir in the garlic and 1 teaspoon of sherry vinegar. Cook until the vinegar has evaporated, 30 to 60 seconds

Step 3

Pour the eggs into the skillet and cook, using a silicone spatula to push and stir from the edges to the center, until the eggs begin to set, about 1 minute.

Transfer the skillet to the oven and bake until just set, 3 to 5 minutes. Remove from the oven and sprinkle with the Parmesan. Return to the oven and bake until the cheese melts, about 1 minute.

Step 4

Remove from the oven. Run the spatula around the edge and under the frittata to loosen, then slide onto a serving plate. Sprinkle with 2 tablespoons of the chives. Set the empty skillet over medium-high, add the remaining ¼ cup vinegar and simmer until reduced to 2 tablespoons, 2 to 4 minutes.

Off heat, stir in the mustard, then stir in the remaining 3 tablespoons butter a piece at a time until melted. Stir in the remaining 2 tablespoons chives, then taste and season with salt and pepper. Cut the frittata into wedges and serve with the sauce on the side.

Featured in