I thought of something. Maybe this recipe for "cheese sauce" can replace the cheese soup:

It consists of butter, flour, milk and grade cheese
(I don't really know the measurements, because I do it on sight, I can look them up if you think this can replace the soup)

Melt the butter and at flour (the same amount as the butter) and stir till it is smooth. Then add the milk and bring to the boil. When it is boiling, add grated cheese.