Preheat oven to 375
1. In a 5-qt Dutch oven over medium high heat, sauté onion in liquid of your choice (balsamic vinegar, olive oil, water) until tender, stirring occasionally.
2. Add rice; cook while stirring until parched and slightly opaque.
3. Add beans, tomatoes, chilies and 3 1/2 cups of water to rice and onion in Dutch oven and bring mixture to boil.
4. Cover tightly place in oven, baking until rice is tender and liquid is absorbed (around 1 hour for brown rice).
5. Add peas and corn, adjust seasonings, and return to oven until heated through.