Meanwhile, spread brown rice out along base of an oven safe casserole dish (2.5 quart/ 2.3 L is the size I used) such that it forms the bottom layer. Top rice with remaining 1 + ¼ cup of salsa to form second layer. Spread onion mixture over salsa. Add black bean/bell pepper/olive mixture over onions and top with shredded cheese.
Place casserole in oven uncovered and allow it to cook for approximately 30-45 minutes or until cheese is bubbling and beginning to brown along the edges.
Remove casserole from oven and allow it to cool for at least 10 minutes before serving (I cut my piece too soon and got the droops). Add more seasoning as desired and serve with another dollop of salsa, guacamole and/or plain yogurt.
Notes
The Chili/Chile: you can use any chili powder (mild/spicy) you choose. Generic "chili powder" found in the grocery store is a spice blend (typically made from a mix of mild chile, onion, salt and herbs) that is generally fairly mild. If you enjoy things on the spicier side, a few ideas: chop up a fresh jalapeno pepper or two; try a warming full-bodied chile powder such as ancho or one with a bit more bite such as chipotle (from powder or chopped from whole in adobo sauce). Alternatively, you could also could also ramp up the heat by using a spicy salsa.
Recipe by Inspired Edibles at https://www.inspirededibles.ca/2012/04/spicy-black-bean-mexican-casserole.html