Bean and Rice Casserole

2 c. uncooked rice
1 med. onion, chopped
1 can (15 1/4 - 19 oz) red kidney beans, drained and rinsed
or equivalent dried, cooked
1 can (15-16 oz) black beans, " " "
or equivalent dried, cooked
1 can (15-19 oz) garbanzo beans, " " "
or equivalent dried, cooked
1 can (14 1/2 - 16 oz) canned, stewed tomatoes, drained *
1 can (4 oz) chopped mild chiles, drained
10 oz. frozen green peas, thawed by placing under running water
1 cup frozen corn, " " " " " "

- Preheat oven to 375.
- In a 5-qt dutch oven over medium high heat, "saute" onion in
liquid of your choice (balsamic vinegar gets my vote)
'til tender, stirring occasionally. Add rice, cook while
stirring until parched and opaque.
- Add beans, tomatoes, chiles and 3 1/2 cups of water to rice
and onion in dutch oven and bring mixture to boil.
- Cover tightly place in oven, baking until rice is tender and
liquid is absorbed (around 1 hour for brown rice)
- Add peas and corn, adjust seasonings, and return to oven until heated
through.

Additional notes:

if using no-salt-added tomatoes, reserve the drained liquid
and add water to equal the 3 1/2 cups of liquid.

I add Tabasco sauce to make it a bit spicy.