Get a large plastic bag, and add in the minced garlic, onion salt, pepper, chili powder, bay leaves, Worcestershire sauce, and liquid smoke. Mix them together properly.

Add the beef brisket into the bag, and make sure the mixture covers it evenly.

Now, seal the bag, and let it marinate in the refrigerator overnight.

Get your slow cooker, and transfer the beef brisket to the cooker. Add in the beef broth, and cook on low heat for 8 hours, or till it’s tender.

Now, take the beef brisket out of the slow cooker, then extract 1 cup of the beef juices and set it aside.

Discard the bay leaves and leftover beef juices from the slow cooker.

Get a small bowl, and mix the barbecue sauce and extracted beef juices together.

Return the beef brisket to the slow cooker, and pour the sauce and beef juice mixture over the beef.

Now, cook on high heat for about 20-30 minutes.

Viola! The slow-cooked Texas beef brisket is ready. You can shred, chop, or thinly slice across the grain before serving.