In a medium sized pot with a lid, heat oil over medium heat and add ground buffalo.

Brown meat, breaking large chunks into smaller ones.

Cook for about 5 minutes or until all meat is browned.

Remove from pot and discard excess fat, leaving about 1 tablespoon in the pot.

Bring back to medium heat, add onion, red bell pepper, green bell pepper and poblano pepper (if using) and cook over medium heat for about 5 minutes, scraping bottom from time to time to get all the browned bits of meat folded in with the vegetables.

Add jalapeño and cook for another 3 minutes stirring from time to time.

Add garlic, cook for another minute and then add cumin, oregano, coriander, salt and pepper.

Let spices cook until fragrant, stirring constantly, about 1 more minute.

Return browned meat to the pot.

Stir in tomatoes and beef broth, brown sugar, Worcestershire sauce, adobo sauce and bay leaf. Stir and bring to a boil.

Once boiling, taste sauce and adjust salt and pepper to taste.

Lower heat to a slow simmer, cover with a lid and cook for about 30 minutes.

Add beans and continue simmering, covered, for another 10 minutes or until beans are warmed through.

Serve in bowls and garnish with chopped cilantro and green onions.

Recipe Variation 
To add a smoky depth of flavor, you can roast the Poblano or Anaheim pepper before adding. Using tongs, hold the pepper over a high heat gas flame, charring all over for about five minutes. You want the pepper skin to have a very dark color on all sides. When done, place in an airtight container and let stand for about five minutes. Using plastic gloves to protect your fingers, rub the skin off and discard. Open the pepper and remove veins and seeds and discard the top or stem. Chop and add to recipe along with the jalapeno pepper.