Can you use corn starch instead of flour to make it gluten free,also gluten free pasta

What this recipe makes is a classic béchamel, and turns it into a mornay by adding in the extra ingedients. You could make a white sauce with cornstarch, and then add the remaining ingredients. You would use different amounts of cornstarch than flour, and would need to look up the recipe to make a medium white sauce with cornstarch- I believe the Argo website has a good one. So long as you grate your own cheese and don't use a ready grated one, your sauce would be gluten free with this method. I am not familiar with using gluten free pasta of any sort, so I can't help you there. The sauce is a basic cheese sauce, and would be tasty over all sorts of things- pasta or vegetable. If you have a favorite pasta, I would think it ought to work out just fine. So long as you don't overcook the pasta, at least.