Preheat the oven to 350°F (175°C).
In a large bowl, combine the cream cheese, mayonnaise, and sour cream.
Add the Parmigiano Reggiano, Pecorino Romano cheese, and minced garlic, and stir to combine.
Stir in the chopped artichoke hearts and spinach.
Season the dip with salt and pepper, to taste.
Transfer the dip to a 9-inch baking dish.
Bake for 20-25 minutes, or until the dip is hot and bubbly.
Serve immediately with your favorite keto-friendly vegetables or crackers.