This will sound weird, but it's good! (--and good for you!) Plus the kids can make it themselves to serve the whole family:

boil enough spaghetti to feed the family

open a can of black beans, drain, add to a saucepan/covered microwaveable bowl
add a jar of salsa to the bowl and heat together

pour over the drained noodles and add fresh tomatoes, avocados and peanuts

garnish with cilantro

Yum! Cheap-oh so very cheap- and actually tasty. :D