Start by preparing your vegetables. Finely chop the onion and chop the red and green bell peppers into small pieces. Rinse the black beans in a colander under cold water and drain well.
In your slow cooker, combine the brown rice, vegetable stock, chopped onion, red bell pepper, green bell pepper, diced green chiles with juice, and the black beans. Stir gently to mix the ingredients evenly.
Add salt to taste, keeping in mind that the vegetable stock may already contain some salt. Stir again to ensure the seasoning is evenly distributed. Cover the slow cooker and set it to cook on low for 4-5 hours or on high for 2-3 hours, depending on your schedule.
After the cooking time is up, check to see if the rice is tender and has absorbed most of the liquid. If it’s still a bit crunchy, let it cook for an additional 30 minutes.
Once the rice is fully cooked, give it a good stir. Serve the bowls warm, allowing everyone to customize their toppings. Consider adding avocado, cilantro, lime, or your favorite salsa for an extra burst of flavor!