Have ready a Crockpot or other slow-cooker.
In a large non-stick frying pan, fry:
2 onions, chopped
3 cloves garlic, chopped
2 Tablespoons vegetable oil
Add and fry for a few minutes until the chicken is somewhat browned and spices are fragrant:
2 Tablespoons gluten free chili powder
1 Tablespoon whole cumin seeds
1 Tablespoon dried oregano
1 teaspoon fresh ground black pepper
1 teaspoon sea salt
1 1/2 pounds boneless chicken, chopped up
2 14-ounce cans of diced gluten free tomatoes
19 ounce can of gluten free black beans, drained and rinsed
Stir is all up, bring it to a simmer and transfer to the crockpot. Cook on low (slowcookers have heat settings of high and low), for 4-8 hours. Adjust the seasoning with a 1/2 teaspoon of sugar if necessary.
Serve with rice, gluten free cornbread or your favorite choice of starch, and with garnishes of diced scallions, gluten free sour cream, grated cheddar etc.
To serve food to gluten-free friends, check carefully with the manufacturers, or on the reputable internet-based gluten free food lists, making sure that all ingredients including spices are gluten free. Or, ask your friends which brands are safe for them to eat. They will appreciate your concern!