Prepare the Spinach
If using fresh spinach, rinse thoroughly and cook it in a large skillet over medium heat with a splash of water until wilted. Drain well and set aside. For frozen spinach, thaw completely and squeeze out excess water.
Make the Garlic Base
Melt butter in a large skillet over medium heat. Add the minced garlic and sauté for 1-2 minutes, until fragrant.
Create the Cream Sauce
Pour in the heavy cream and bring it to a gentle simmer. Add the Parmesan cheese and stir until fully melted and combined.
Season the Sauce
Stir in ground nutmeg, salt, and pepper to taste. Adjust seasonings as needed.
Incorporate the Spinach
Add the cooked spinach to the skillet, stirring to coat it evenly in the sauce. Cook for an additional 2-3 minutes, allowing the flavors to meld together.
Serve Warm
Transfer to a serving dish and garnish with extra Parmesan cheese or a pinch of red pepper flakes for a touch of heat.