What are some good recipes for someone who doesn't like a lot of flavor?

My boyfriend and I enjoy "double-dating" with his grandparents: we get together maybe once a week and one couple or the other cooks. I usually cook with a lot of flavor, but they prefer plain food without spices or a whole lot of other embellishment. I am looking for some recipes that are not too flavorful so I've got a wider variety of meals to prepare when we cook.

Some stuff they like already, as examples of what's not too crazy:

-ANYTHING meat and potatoes, pretty much

-Chicken and noodles casserole

-Barbecued beef

-Chicken or pork with Shake 'n Bake

-Pot roast

-Some fish (usually broiled): tilapia; flounder; salmon prepared as a loaf

-Meatloaf

-Chicken soup

-Beef stew

-Etc.

We usually have stuff like rice, rolls, salad, mashed/baked potatoes, cooked vegetables (corn, string beans, etc.), or raw vegetables with ranch dip as sides, which is working really well. Obviously meat is not a problem for us. :-) Thanks for any good main dishes you can share!