Dump the cream of mushroom soup, and replace it with dried wild mushrooms, water and milk powder. Costco sometimes sells big plastic jars of dried mushrooms for cheap, or try Italian food stores (better mushrooms, more expensive) or Chinese food stores (worse mushrooms, cheaper).

East Indian food stores are good places to find dried onions in decent quantities at a reasonable price. Even if you have a dehydrator, it stinks up the house, so I just buy mine.

This stroganoff recipe is half-decent, but might really be better with that dehy sour cream, if it's any good:

200 g noodles
3/4 cup dehy ground beef (orig 1/2 lb)
3/8 cup dried wild mushrooms chopped
2 tbsp milk powder
1/4 tsp corn starch
1 tbsp dried onions, chopped
1/2 tsp garlic powder
1 tbsp dried parsley
1 tsp salt
1 tsp pepper

It would probably be better with steak rather than ground beef too - that will have to be something to test this summer.