In a large pot or large saucepan, melt the 2 tablespoons unsalted butter over medium-low heat.
Add the ½ cup finely chopped shallot and sauté for 2-3 minutes, stirring occasionally, until they begin to soften. Do not let them brown.
Add the chopped 2 garlic cloves and 1 pinch of red pepper flakes and sauté for an additional minute until the garlic becomes fragrant.
Slowly pour in the 1 cup heavy cream and add the 4 ounces softened cream cheese. Stir until the cream cheese has melted. I use a spoon to break the cream cheese into smaller pieces to help it melt faster. The cream cheese should take about 8 minutes to melt.
Add the ½ cup Asiago cheese and ⅛ teaspoon ground nutmeg. Stir to combine.
Stir in the 12 ounces of baby spinach breaking up any clumps of spinach.
Let the spinach cook for 6 minutes until it is heated through.
Season with salt and freshly ground black pepper to taste.
Sprinkle with additional Asiago cheese and a splash of lemon juice.
Notes
If using frozen spinach, you will want to defrost the spinach and then squeeze out as much excess water as you can. If you want to you can use a paper towel to blot away the extra moisture. If you don't the sauce will become watery.Don't try to use additional milk instead of heavy cream. Milk is more likely to separate and won't give you the same creamy consistency.Don't use pre-shredded cheese shred your own. Shredded cheese often has additives that can prohibit melting and make the sauce clumpy.For a looser consistency, add a little more heavy cream.For some extra crunch, saute panko bread crumbs in a little butter and sprinkle them on top of the dish before serving.Storage
Refrigerate leftovers in an airtight container for 2 to 3 days.
Freezing creamed spinach is not recommended as it may cause the cream to split.
Reheat in a saucepan on the stove. You may need to add an additional splash of cream.