and avoid boiling it.

For a result closer to the original recipe, half-and-half is generally a better substitute than regular milk.

Why did my Parmesan sauce become grainy?

A sauce can become grainy when the heat is too high or when the cheese is added too quickly. Lower the heat before adding Parmesan and stir in small portions.

Packaged grated cheese may also contain additives that affect melting, which is why freshly grated Parmesan is recommended.

Can I make this recipe without flour?

Yes. The flour creates a light crust and helps thicken the sauce, but it can be omitted.