Prep the dried chiles: Place torn dried chiles in a small bowl and cover with hot water. Soak 10–15 minutes until soft.
Blend with a splash of the soaking water to make a smooth paste. Set aside.
Brown the beef: Heat a large Dutch oven over medium-high. Add oil, then half the beef in a single layer.
Sear 3–4 minutes per side until browned. Remove to a plate and repeat with the remaining beef. Browning builds flavor—don’t rush this step.
Soften aromatics: Reduce heat to medium.
Add onion and a pinch of salt. Cook 5–7 minutes, stirring, until translucent and lightly browned. Add garlic and jalapeño; cook 1 minute until fragrant.
Bloom the spices: Stir in chili powder, cumin, smoked paprika, oregano, black pepper, and tomato paste.
Cook 1–2 minutes, stirring, until the tomato paste darkens slightly and the spices smell toasty.
Deglaze: Pour in 1/2 cup beef broth, scraping up browned bits from the bottom of the pot. Return browned beef (and any juices) to the pot.
Add chile paste and simmer: Stir in the blended dried-chile paste, remaining beef broth, bay leaf, cocoa or chocolate if using, and 1 teaspoon salt. Bring to a gentle boil, then reduce to a low simmer.
Slow cook: Cover partially and simmer 1.5–2 hours, stirring occasionally, until the beef is very tender.
Add a splash of water or broth if the chili gets too thick before the beef softens.
Finish and balance: Stir in vinegar or lime juice. Taste and adjust salt, pepper, and heat. For more heat, add a pinch of cayenne or chopped jalapeño.
For more smokiness, add a bit more smoked paprika.
Serve: Ladle into bowls and top with cilantro, sour cream, cheese, scallions, or avocado. Keep toppings low carb by choosing full-fat dairy and skipping tortilla chips.