The basic recipe calls for a 1.5 quart casserole dish. A 13x9 pan holds approx 3 quarts, so you will need to double the recipe.
Personally I'd double it and throw in another can of beans. I always think the orig. recipe is lite for the size they say so I add more beans then to.
just have a couple extra cans and add some more if your pan doesn't look full enough.
Canned string beans?
I use canned, salt free, french cut green beans.