Roasted Cauliflower and Goat Cheese Frittata

Roasting the cauliflower under the broiler gives it toasty, golden edges in just minutes, while the goat cheese, dill, and quickly pickled red onion add tons of flavor to this hearty frittata.

• 1 small red onion, halved and thinly sliced lengthwise
• 2 Tbs. distilled white vinegar
• Kosher salt
• 2 cups 1-inch cauliflower florets (about 1/2 small head)
• 2 Tbs. plus 2 tsp. extra-virgin olive oil
• Freshly ground black pepper
• 8 large eggs
• 2 Tbs. chopped fresh dill
• 1/2 tsp. whole-grain mustard
• 2 Tbs. unsalted butter
• 6 oz. fresh goat cheese, crumbled (1-1/2 cups)

Position a rack about 6 inches from the broiler and heat the broiler on high.

Combine the onion, vinegar, and 1/2 tsp. salt in a small bowl; let sit for 10 minutes and then drain and pat the onion dry. Set aside.

Meanwhile, on a large rimmed baking sheet, toss the cauliflower with 2 tsp. of the oil, 1/2 tsp. salt, and 1/4 tsp. pepper. Broil, tossing once or twice, until the edges are golden, 3 to 6 minutes.

Reposition the rack in the center of the oven and set the oven to 400°F.

Whisk the eggs, dill, mustard, 1/2 tsp. salt, and 1/2 tsp. pepper in a medium bowl.

Heat the remaining 2 Tbs. oil and the butter in a 12-inch ovenproof skillet over medium-high heat until the butter melts. Add the onion and cook, stirring occasionally, until some of the pieces are dark golden brown, about 3minutes. Remove the skillet from the heat, stir in the roasted cauliflower, and then slowly pour in the egg mixture, redistributing the vegetables evenly. Sprinkle the goat cheese on top and bake until the eggs are set in the center, about 10 minutes. Let rest for 5 minutes and then use a silicone spatula to slide the frittata onto a serving plate or cutting board. Slice into wedges and serve.