In a large bowl (or resealable plastic storage bag if you're tailgating) combine the chicken and the Stubb's Sweet Black Pepper Anytime Sauce, turning until chicken is well coated. Refrigerate for at least an hour to marinade.
In a glass measuring cup, combine the vinegar, water, kosher salt and sugar Microwave on high for 2-3 minutes, stirring occasionally, until the sugar and salt have dissolved.
Place the onions, garlic and jalapeño in a medium bowl and cover with the brining liquid -- pressing the onion into the liquid to cover. Let rest until liquid reaches room temperature, then refrigerate for an hour to quick pickle the veg.
Use the grill or a gas stovetop to char the poblano peppers, placing the peppers over the flame until the skin is blackened, turning occasionally about 10 minutes. Transfer the peppers to a small paper bag and seal the end by rolling the bag up tightly. Let the peppers rest for about 10 minutes until they are cool enough to handle, and use your hands to slough off the blackened skins. Remove the seeds from the peppers and slice into thin strips. Transfer to a container to transport and serve.
Grill the chicken on a medium high heat (about 450°), turning occasionally until cooked, about 9-10 minutes. Transfer chicken to a cutting board and use a cleaver or sharp knife to chop the chicken thighs into bite sized chunks. Transfer chicken to a platter to serve.
Assemble the sandwiches: piling on the chicken, slices of cheese, strips of poblano pepper and pickled onions and a few fresh sprigs of cilantro. Drizzle with Sweet Heat barbecue sauce and DIG IN!
can be doubled or tripled but you don't need to increase the amount of pickled onions, this recipe makes about 2 cups of pickled onion. (also delicious on quesadillas, fish dip (on this site) or other sandwiches or tacos)