Step 1

Place a large pot or Dutch oven over medium-high heat. Add beef and cook, breaking up with the back of a spoon, until cooked through, about 6 minutes. Using a slotted spoon, transfer beef to paper towels to drain. Discard all but 1 tablespoon fat from pan.

Step 2

Return pot to medium-high heat. Add onions, garlic, jalapeno, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper; cook until onions soften, about 6 minutes. Add chili powder, cocoa, and tomato paste; cook until fragrant, about 2 minutes more.

Step 3

Add tomatoes, broth, and cooked beef. Bring to a boil, then reduce heat to medium-low and simmer, partially covered, until thickened slightly, 25 to 30 minutes. Season with salt and pepper; serve with sour cream and chives.