Ricotta adds cheesy heft to this weeknight staple that’s loaded with spinach, mushrooms, and corn and studded with sun-dried tomatoes and feta cheese. It’s a farmers’ market in a skillet.
Place an oven rack in the second highest position and preheat the broiler.
In a medium bowl, whisk together the eggs, ricotta, Parmesan, milk, nutmeg, ½ tsp salt, and a few grinds of pepper. Set aside.
Heat a 12-in [30.5-cm] oven-safe skillet over medium-high heat, and add the olive oil. When the oil shimmers, add the onion and sauté until it begins t