1. Combine 3 tablespoons salt, 4 quarts water, and beans in large Dutch oven and bring to boil over high heat. Remove pot from heat, cover, and let stand 1 hour. Drain and rinse well.

2. Adjust oven rack to lower-middle position and heat oven to 300 degrees. Place ancho chiles in 12-inch skillet set over medium-high heat; toast, stirring frequently, until flesh is fragrant, 4 to 6 minutes, reducing heat if chiles begin to smoke. Transfer to bowl of food processor and cool. Do not wash out skillet.

3. Add árbol chiles, cornmeal, oregano, cumin, cocoa, and ½ teaspoon salt to food processor with toasted ancho chiles; process until finely ground, about 2 minutes. With processor running, very slowly add ½ cup broth until smooth paste forms, about 45 seconds, scraping down sides of bowl as necessary. Transfer paste to small bowl. Place onions in now-empty processor bowl and pulse until roughly chopped, about four 1-second pulses. Add jalapeños and pulse until consistency of chunky salsa, about four 1-second pulses, scraping down bowl as necessary.

4. Heat 1 tablespoon oil in large Dutch oven over medium-high heat. Add onion mixture and cook, stirring occasionally, until moisture has evaporated and vegetables are softened, 7 to 9 minutes. Add garlic and cook until fragrant, about 1 minute. Add chili paste, tomatoes, and molasses; stir until chili paste is thoroughly combined. Add remaining 2 cups broth and drained beans; bring to boil, then reduce heat to simmer.

5. Meanwhile, heat 1 tablespoon oil in 12-inch skillet over medium-high heat until shimmering. Pat beef dry with paper towels and sprinkle with 1 teaspoon salt. Add half of beef and cook until browned on all sides, about 10 minutes. Transfer meat to Dutch oven. Add ½ bottle lager to skillet, scraping bottom of pan to loosen any browned bits, and bring to simmer. Transfer lager to Dutch oven. Repeat with remaining tablespoon oil, steak, and lager. Once last addition of lager has been added to Dutch oven, stir to combine and return mixture to simmer.

6. Cover pot and transfer to oven. Cook until meat and beans are fully tender, 1½ to 2 hours. Let chili stand, uncovered, 10 minutes. Stir well and season to taste with salt before serving.