2 pounds (32 ounces) ounces fresh baby spinach or regular spinach leaves
1 small yellow onion, finely chopped
3 small garlic cloves, minced
4 tablespoons unsalted butter
1 pound mushrooms, thinly sliced (I use creminis)
1 cup heavy cream
3/4 teaspoon table salt
Freshly ground black pepper
1/4 teaspoon freshly grated nutmeg (optional; I skip this)
12 large eggs
6 tablespoons finely grated Parmesan cheese