Pork Tenderloins: the night before preparing the tacos: Add all ingredients except the pork tenderloins to a gallon size zipper close plastic bag. Seal bag and shake to fully combine marinade ingredients. Add the pork tenderloins and seal squeezing out as much air as possible. Massage the marinade to cover the pork tenderloins (from the outside of the bag) and refrigerate overnight.
Preparing the slaw (minimum 1 hour prior to serving tacos however may be done earlier): Combine the broccoli stem matchsticks, red onion and jalapeno in a quart Mason jar or other sealable jar. In a small saucepan over medium heat, combine the vinegar, sugar and salt and heat just until the sugar and salt have dissolved. Pour into the jar and seal. Shake to coat the vegetables. Place in the refrigerator for an hour (or more).
Day of grilling: Remove the pork tenderloins from the marinade (allowing excess marinate to drain into the bag) and allow them to sit at room temperature for 30 minutes prior to grilling. Discard the marinade.
Thread 5 grape tomatoes per bamboo skewer and lightly brush with olive oil, and sprinkle with salt and pepper.
Heat the grill to medium-high (375 degrees) (note: only half of a four burner gas grill will be needed). Brush and oil the grill. Place the pork tenderloins on the grill and turn every 3-5 minutes to allow each side to develop a crust and not burn. The tenderloins should be removed when the internal temperature reaches 145-150 degrees (it will continue to cook while resting off the grill). This should take 12-15 minutes. Remove and allow to rest until the tomatoes are done.
Brush and oil the grill again if needed. Place the tomato skewers with a piece of foil on the grill underneath the exposed ends of the skewers. Rotate the skewers as soon as the tomatoes begin to blister to cook on all sides. Total cooking time is only 2-3 minutes. Remove from grill.
To assemble the tacos: Slice the pork tenderloin thinly (1/8-1/4-inch thickness). Place 3-4 slices on a warmed corn tortilla. Sprinkle with an ounce of cheese, followed by 1-2 tablespoons of pickled slaw, 3-4 blistered tomatoes and any garnish (if desired).