How to Make It
Stir together flour, ancho chile powder, cumin, salt, and oregano in a small bowl. Sprinkle spice mixture evenly on each side of beef brisket cubes, and set aside.
Combine black beans, tomatoes, bell pepper, onion, garlic, and beef broth in a 6- to 7-quart slow cooker.
Heat 2 tablespoons of the oil in a large skillet over medium-high. Add half of brisket cubes; cook, stirring often, until browned on all sides, 5 to 7 minutes. Transfer beef to slow cooker. Repeat procedure with remaining oil and brisket.
Cover and cook on LOW 8 hours. Uncover and cook until slightly thickened, about 1 hour.