Upon my child asking for mac and cheese for the 3rd time in 2 days, I decided to try a vegan version of my own devising. For the sauce I cooked up some red lentils and pureed them with some cashews, olive oil and some of the pasta cooking water until it was smooth. Salt and peppered the sauce to taste (we like lots of pepper in our mac and cheese sauce). Then I put it over the cooked noodles. Looks just like home-made cheese sauce, has no dairy in it.
I think next time, though I'll either cook or at least soak the cashews to make them blend a bit smoother. It was good for a quick lunch.