Rub the pork tenderloin with 3 tbsp of Steve's BBQ rub (link to my spice rub recipe is found here)
Mix the remaining ingredients together and pour in a baking casserole dish.
Place the beans and pork tenderloin in a smoker. Using wood of your choice (I use apple, cherry, and hickory different times and all are good!). Try to keep the smoker at about 225F. If you are smoking any other meat (ribs, boston butt, brisket, etc) place the bean on the bottom rack to catch the drippings.
After 3 hours in the smoker, remove the pork tenderloin and chop it up into small chunks. Stir it in with the beans and let them cook in the smoker for another 2-3 hours.
Notes
If you do not have a smoker, this recipe will work great using an oven as well. The beans taste wonderful out of the oven but they do not have the smokey flavour. Follow the above recipe but cook in a 325 oven for 3-4 hours or until onions are tender