Using a small bowl, combine the spices for the rub. Generously apply rub to all sides of brisket; let sit at room temperature for an hour or in refrigerator overnight.

Preheat smoker to 225°-250°F.

Once the smoker has reached a stable temperature, add the wood chunks directly to the coals. Put the grate in place and put the brisket on the grates with the fat cap (the fattier side) up. Insert a probe thermometer into the center of the brisket, close the lid, and walk away.

Occasionally check the temperature of the smoker to ensure it stays within 225°-250°F.

When the internal temperature of the brisket reaches 165°F, remove the brisket and place in the disposable aluminum pan. Pour the stock into the pan and then wrap the pan (brisket and all) and place it back on the smoker.

When the internal temperature of the brisket reaches ~190°, remove the brisket from the smoker. Leave the brisket in the aluminum pan and let it rest for at least 30 minutes before slicing.

When slicing, I typically remove and discard most of the fat cap. Then I slice the meat itself into large slices. These can either be frozen or stored in the refrigerator. Then when making the tacos (or other recipe using smoked brisket) I chop several slices into small pieces and then reheat it in a dry skillet.

Add all guacamole ingredients to a medium bowl. Using a fork, mash until well combined.

Spread ~2 Tbsp of guacamole onto each of the flour tortillas.

Spread chopped brisket evenly over tortillas and then top with chopped tomatoes and onions.

Sprinkle freshly chopped cilantro and squeeze a fresh lime over each taco before serving.