Halve, peel, and dice the onion. Core, seed, and remove the white ribs from the bell pepper, then finely dice. Mince or grate the garlic. Thinly slice the scallions, keeping the greens and whites separate. Drain and rinse the black beans.

Heat a drizzle of oil in a large pan over medium-high heat. Add the chicken sausage to the pan and cook for 4-5 minutes, turning occasionally, until browned. Set aside, then slice into 1/2-inch rounds once cool enough to handle.

Heat another drizzle of oil in the same pan over medium-high heat. Add the onions, peppers, and scallion whites to the pan and cook, tossing, for 4-5 minutes, until softened. Add the garlic, cumin, and chili powder to the pan and cook for 1-2 more minutes, until fragrant.

Add the diced tomatoes, black beans, vegetable stock concentrate, oregano, and 2 cups water to the pan. Bring to a boil, then reduce to a simmer for 10-15 minutes, stirring occasionally. Stir the chicken sausage into the pan. Taste and season with salt and pepper.

Serve the chili divided between bowls, dolloped with sour cream and garnished with scallion greens. Enjoy!