This recipe is a little different from the norm because you make an actual sauce instead of using a can of cream of blank soup, and it uses corn instead of peas. You can definitely use peas instead, though, or go on and add 8 oz of them in addition to the corn, why not?
My version is pretty loyal to the original, but I add garlic and cut the cheese into cubes instead of shredding it. Shredded cheddar kind of disappears into the casserole, but cubes give you little pockets of melty cheesiness.
For the pasta, you can use pretty much anything. I think of egg noodles as being the traditional tuna casserole pasta, and that's very good, but it's also good with macaroni, penne, fusilli, shells, or other short shapes. I'd stay away from something long like spaghetti or very tiny like orzo, but pretty much anything else is good. Whole wheat pasta works nicely, too.
If you're looking for a decent whole wheat pasta option, I have tried a lot of them and the company Bionaturae makes by far the best. Many of the other brands are pretty gross. DeLallo makes pretty good whole wheat pasta as well, but Bionaturae tastes almost like regular white pasta. I've taken to ordering bulk packs of 6 lbs of Bionaturae on Amazon because only one local store sells it, they only have penne, and it's $4 a pound at the store.
From Scratch Tuna Casserole
1 lb short pasta of your choice
8 oz frozen corn
4 Tbsp butter
2 cloves garlic, minced
4 Tbsp flour
2 1/2 C milk
1 tsp salt
1/2 tsp pepper
10 oz cubed cheddar
1/4 C minced fresh parsley
2 cans tuna, drained
Preheat oven to 350. Grease a 9 by 13 dish and set aside
Boil pasta in salted water and add the frozen corn when the pasta is 2 or 3 minutes from being done. When the pasta is a little less cooked than you'd prefer (it will continue cooking in the oven), drain it.
While the noodles cook, melt the butter in a small saucepan over medium and add garlic. Saute the garlic for a minute or so, but don't let it brown. Increase the heat to medium-high, add the flour and saute for a couple minutes longer, until you have a nice, smooth roux. Pour in the milk 1/4 C at a time for the first cup, stirring well after each addition until the sauce is completely smooth. After the first cup of milk has been added, you should be able to add the rest of the milk all at once. Cook, stirring constantly, until the sauce comes to a simmer and thickens. Continue cooking and stirring for 2 or so minutes longer. Remove pan from heat and add the salt and pepper.
Stir sauce into cooked noodles. Stir in tuna, parsley, and cheese cubes. Taste and add more salt and pepper if needed.
Spread pasta in greased baking dish. Bake 20-30 minutes, until hot and golden on top.