Baked Ziti with Spinach and Gorgonzola

INGREDIENTS

2 1/2 tbsp

unsalted butter

2 cups

Classic Béchamel (recipe below), hot

4 oz

full-fat Gorgonzola cheese, crumbled (about 2/3 cup)

1 lb

flat-leaf spinach

medium onion, minced

Salt

freshly grated nutmeg

1 lb

ziti (recommended: Barilla Plus®)

1/4 cup

freshly grated Parmigiano-Reggiano cheese

3 cups

whole milk

6 tbsp

unsalted butter

4 1/2 tbsp

unbleached all-purpose flour

1/2 tsp

salt, or to taste