Onion Frittata with Sherry Vinegar Sauce

Ingredienser

8 large eggs

Kosher salt and ground black pepper

4 tablespoons (½ stick) salted butter, cut into 4 pieces, divided

1 medium yellow onion, chopped (about 1 cup)

1 medium garlic clove, finely grated

¼ cup plus 1 teaspoon sherry vinegar

1 ounce grated Parmesan cheese (½ cup)

4 tablespoons minced fresh chives, divided

1 tablespoon whole-grain mustard

Fremgangsmåte

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.

In a 10-inch oven-safe 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 heat to medium-high and cook, stirring, 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.

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.

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 and 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.

Notater

Don’t use a conventional skillet; nonstick is essential for helping the frittata slide out of the pan with ease.

Cookbook author Deborah Madison’s unhurried and unfussy approach to cooking inspired this recipe for turning basic eggs into a rich and satisfying meal. The sautéed onion gives the frittata a sweet succulence that is complemented by a butter-vinegar sauce and fresh chives. If you like, use red wine vinegar in place of the sherry vinegar and 2 ounces (1/2 cup) shredded Gruyère cheese instead of Parmesan. A pile of simply dressed greens and a crusty baguette make a great accompaniment.