When I was pregnant, my mother-in-law helped me make several casseroles to freeze. We're still eating them, but the ones with ham have had some problems. At first, it was just ham, vegetables, and noodles with no sauce to hold it all together. So I started adding cream of mushroom soup. But the ham is still really salty. Is there something else I can add in addition to or in place of the cream of mushroom soup to help, or should we just toss the rest of the ham casseroles? Thanks!
You need to add bulky things with no salt, so that it'll average out to a saltiness you're okay with.
Although cream of mushroom soup sounds like a nice easy way to add some goopiness, it's probably pretty salty. If you can find low- or no-sodium soup, that'd be a much better choice. That kind of thing might be easier to find in fancy/organic/"healthy" brands. If you're willing to make your own soup/sauce, you can easily make it salt-free, but it sounds like you're looking for quick and easy options.
You could also try adding more vegetables and noodles without salt. (Starchy things like potatoes can also work well, but maybe you prefer noodles since they're already in there.) If you end up needing more goopy stuff to hold it together, again, try to find something sodium-free or low-sodium.
But there's not really any avoiding the main issue: you have to add a bunch of stuff without salt, so you're kind of going to have to turn your casserole into a bigger casserole.
If you're looking for something with the glue power of a cream soup, without the same salt level, consider making a white sauce (aka. béchamel).
It's a cooked mix of butter, flour and milk (possibly with some seasonings, like nutmeg or black pepper).
Try adding things that typically need salt...potatoes, noodles, eggs, broccoli, cauliflower, etc...but of course let the ham salt the food. The soup is also salty, so that may be why it's not getting better. Also, for the future, soak the ham in water for 24-48 hours before cooking it. (Change the water every few hours or keep refrigerated) Hams are typically salt cured and therefore quite salty.