Brown the meat
Add onion to the Dutch oven and sauté until translucent -- 3 to 5 minutes.
Add garlic and cook 1 more minute.
Return the meat to the Dutch oven.
Gradually add 1 can beef broth and deglaze by scraping up the brown bits from the bottom of the Dutch oven.
Add chili powder, cumin, and tomatoes. Reduce heat to medium low, cover, and simmer for 1 hour.
Puree the chiles: In a small saucepan over high heat, bring the remaining can of beef broth to a boil.
Add ancho chiles and let stand 15 minutes to hydrate.
Remove and discard stems.
Place chili mixture and liquid in a blender or food processor and blend until smooth -- 2 to 3 minutes.
Finish the chili: In a small bowl, whisk the masa and water together.
Stir masa mixture into the chili. Add ancho chili mixture, pinto beans, salt, and vinegar.
Simmer uncovered for 15 minutes. Serve hot.