Begin by bringing a large pot of salted water to a rolling boil. Add 20 ounces of cheese tortellini and cook according to the package instructions, usually about 3–5 minutes until they float to the surface and are al dente. Once cooked, drain the tortellini in a colander and set aside.

In a medium saucepan, melt 4 tablespoons of salted butter over medium-low heat. Add 4 cloves of minced garlic and sauté for about 1–2 minutes until fragrant but not browned.

Sprinkle in ¼ cup of flour, 1 teaspoon of kosher salt, and ¼ teaspoon of pepper into the pan. Whisk continually for 3-5 minutes, allowing the mixture to bubble and turn a light golden color.

Gradually pour in 4 cups of milk while whisking vigorously to prevent any lumps. Increase the heat to medium and keep stirring until the sauce thickens and begins to bubble, about 5-7 minutes.

Remove the saucepan from the heat and stir in 1 cup of shredded parmesan and 1 cup of shredded mozzarella cheese. Mix until all the cheese is melted and incorporated.

Gently fold in the cooked tortellini, 6 cups of fresh spinach, and the chopped artichoke hearts from a 14-ounce can. Stir until the spinach wilts and everything is well combined.

Taste the dish and adjust seasoning with more salt and pepper if necessary. Once everything is warm and evenly mixed, serve hot in bowls, garnished with extra cheese if desired.