Lightly brown ground beef in Dutch oven over medium heat. Stir in
onion and continue cooking until onion is transparent. Drain off fat.
Stir in tomatoes (break up with a fork) with their liquid. Add
peppers, chili powder, salt, cumin, and oregano. Adjust heat so that
sauce simmers gently.
Drain beans, reserving liquid. Whirl a third of the beans in a food
processor until smooth, adding their liquid as needed. Stir the
processed beans into the meat mixture. Add drained beans, along with
as much of the reserved liquid as will fit in the pot. Cook,
uncovered, stirring occasionally, for 30 minutes.