Add all the ingredients for the taco filling into a slow cooker. Set to low for 4-5 hours until the chicken shreds easily with a fork.
Remove the chicken breasts from the slow cooker and place in a large bowl. Shred with two forks and set aside.
Pour out the sauce from the slow cooker into a large measuring cup or bowl. Add the shredded chicken back to the slow cooker and add in enough of the sauce to coat the shredded chicken, but not too much to make it loose. About 2 cups should be enough.
Set your slow cooker to it’s “keep warm” or “buffet setting” while you make the taco shells.
Take a corn tortilla and make a cut from the center out to one side. Place it into a muffin tin pushing down on the bottom and forming the sides around to make a cup. They don’t have to look perfect, just fit them in as best as you can.
Repeat with the other 11 tortillas, spray with cooking spray and bake for 8-10 minutes at 400°F until crisp and slightly browned.
Remove the taco shells to a platter and start assembling the tacos.
Place a large scoop of shredded chicken into the center of a taco shell, then top with a scoop of guacamole and a few diced peppers.
Place the pumpkin sriracha sauce into a sandwich bag and snip of a small pieces of one corner. Squeeze the sauce onto the tops of the tacos. Alternately, you can place a dollop of the sauce on top of the guacamole if you don’t want to use the sandwich bag.
If you don’t want to make your own taco shells, you can use a store bought taco shell or a corn or flour tortilla as a wrap for a soft taco.