Keto Baked Eggs Florentine

Name: Keto Baked Eggs Florentine
Ingredients: Kosher salt and freshly ground black pepper; One 5-ounce container baby spinach; 1 tablespoon unsalted butter; 1 shallot, thinly sliced; 1 clove garlic, minced; 3 ounces thin-sliced deli ham, preferably low or no sugar added, coarsely chopped; 1 1/2 cups heavy cream; 1/2 teaspoon whole-ground mustard; 1/8 teaspoon freshly grated nutmeg; 1/3 cup grated Parmesan; 4 large eggs; 1/4 cup grated mozzarella; 2 tablespoons fresh parsley leaves, chopped