This dish does not have a strong 'fishy' taste, for those of you who, like my family, are not overly fond of 'fishy' dishes.
This is the first dish I learned to cook after moving into my own home. (Probably because of how simple it is.) Mama gave me her recipe, one she had added her own touches to after receiving it. Over the years, I've added extra tuna, extra salad dressing and lots of extra cheese. You'll definitely need a BIG casserole dish to hold this one!
Make sure tuna is very well drained. Otherwise, your casserole will be slightly runny, especially if you're lucky enough to have any left-overs.
Mix tuna, diced onions and salad dressing right in a 9x13 glass baking dish, adding salt and pepper to taste(actually the casserole dish I use is slightly bigger as my 9x13 nestles inside of it in the cabinets). The original recipe calls for 1/4 cp of salad dressing, but over the years I've discovered the end result is creamier if you add more.
In a large saucepan, heat cream of chicken soup and milk over medium to med-high heat until well blended. Add shredded chedder cheese and continue heating, stirring frequently, until smooth and creamy. As with the salad dressing, I add more cheese than originally called for. An extra cup, to be exact.
While soup mixture is heating, boil noodles until tender. Drain.
Mix soup mixture with tuna mixture in casserole dish, mixing well. Add drained noodles, again, mixing well. Some people may find it easier to mix all the ingredients in a very large bowl before pouring in the baking dish. I simply like having one less bowl to wash. ;)
Bake, uncovered, 30 minutes, or until top has a little browning and casserole is bubbling. (cooking time may need to be adjusted, depending on oven)