3 large Spanish yellow onions, diced 2 tablespoons vegetable or olive oil 1 ½ tablespoons kosher salt, plus more to taste 3 red bell peppers, cored, seeded and diced 8 large garlic cloves, chopped or grated on a Microplane 1 tablespoon dried oregano (preferably Mexican oregano) 3 tablespoons double-concentrate tomato paste (or 1 6-ounce can tomato paste) ¼ cup chili powder, plus more to taste ¼ cup plus 2 tablespoons guajillo or pasilla chile powder (or a combination), plus more to taste ¼ cup plus 1 tablespoon ground cumin, plus more to taste 1 ½ pounds ground beef chuck (80% lean/20% fat) 1 ½ pounds ground pork (80% lean/20% fat) 1 (28-ounce) can plus 1 (14-ounce) can crushed tomatoes (preferably fire-roasted) 1 tablespoon pureed chipotle chiles in adobo, plus more to taste 4 cups low-sodium chicken stock 2 (15-ounce) can kidney beans, rinsed and drained (preferably low-sodium) 2 (15-ounce) cans pinto beans, rinsed and drained (preferably low-sodium) Mexican crema or sour cream, for garnish Queso fresco, crumbled, for garnish Pickled jalapeño chiles, for garnish 1 white onion, minced, for garnish Fresh cilantro leaves for garnish 1 bunch green onions (light green and white parts), thinly sliced, for garnish