Cook the ground chuck in a nonstick skillet or saute pan over medium-high heat until no longer pink. Drain off any excess liquid or grease. Season with salt, taco seasoning, chili powder and oregano. Set aside.
Heat canola oil over medium-high heat in a Dutch oven or other large, heavy soup pot. Add the onion, reduce heat to medium-low and cook 5-7 minutes or until onion is beginning to soften.
Add the green and red bell peppers and cook 3-4 minutes.
Add the Poblano peppers, the beef, beef broth, tomato sauce, diced tomatoes with green chiles.
Bring to a boil, reduce heat to low, cover slightly and cook 30 minutes or until the vegetables are tender.
Add the brown rice and heat through.
Add half the cilantro, season to taste with salt and black pepper. Add a teaspoon or two of sugar if needed.
Serve in bowls garnished with the remaining cilantro and shedded Cheddar cheese.