I love beans. I can't tell you how much I love beans. I love refried beans. Canned refried beans aren't so good but work in a pinch. They also tend to be expensive.
A better choice? Dehydrated refried beans. They do require a few minutes of cooking and all you need to know is how to boil water. They are also cheaper than their canned counterparts. The fat free kind come in pinto and black bean. I buy them from amazon.com. They taste amazingly good.
(each pack has 6 servings but for me, that usually translates into 2-3 servings)