Step 1

Combine the first 7 ingredients in a small bowl and set aside.

Step 2

Add the beef to a large bowl and season with the black pepper and 1 Tablespoon of the salt.

Step 3

Heat the oil in a large, deep skillet or saute pan over high heat. Add about 1/3 of the beef to the skillet. Let the meat sit for a minute or so, then stir them up. Cook for another couple of minutes, then transfer the meat to the crock of a 6-quart slow cooker.

Step 4

Repeat with remaining beef, adding it to the skillet in two more batches and browning them in spots. Add more oil between batches, if necessary.

Step 5

When you're finished with the beef, add the onion, celery, and 1 Tablespoon of the remaining salt to the skillet and cook, stirring, until the vegetables begin to soften, about 2 minutes. Add garlic, jalapenos, and spice mixture and cook for another minute.

Step 6

Pour in the stock, tomato paste, and crushed tomatoes and simmer for 3 minutes. Stir in the chocolate, masa harina, and another couple large pinches of salt and cook for another minute.

Step 7

Transfer this mixture to the slow cooker with the beef. Add the water and the squash cubes (if using).

Step 8

Cover and cook on high for 5-6 hours or low for 7-8 hours, stirring only once or twice, until the beef is very tender.

Step 9

Remove the bay leaves and stir in the cilantro and parsley. Serve the chili with garnishes.