I start by heating the olive oil in my Dutch oven over medium heat. Once it's warm, I add the diced chicken and chopped onion together, stirring occasionally so nothing sticks to the bottom. I let this cook for about six to seven minutes, just until the chicken is no longer pink and the onion turns soft and translucent.
Next, I stir in the minced garlic and let it cook for about thirty seconds until it smells fragrant. Then I add the white beans, green chilies, chicken broth, chili powder, cumin, garlic powder, and oregano all at once. I give everything a good stir so the spices distribute evenly through the liquid.
Once everything is combined, I bring the pot to a gentle boil, then reduce the heat to low. I let the chili simmer uncovered for about twenty minutes, which gives the beans time to soften further and the flavors time to meld together. I stir it every few minutes so nothing scorches on the bottom.
After the simmering time is up, I take the pot off the heat completely before stirring in the sour cream. This step matters because adding sour cream to a boiling pot can cause it to separate or curdle. I stir gently until the chili turns a beautiful creamy white color.
Finally, I taste the chili and add salt and pepper as needed, since the broth's sodium level can vary by brand. If I'm using the shredded cheese, I sprinkle it in now and let it melt right into the pot. Then I ladle it into bowls and serve it while it's warm and comforting.