In a large bowl, combine all of the ingredients. Season with salt and pepper. Set aside until ready to serve.
In a large non-stick skillet over medium-high heat, brown the tempeh strips in the oil for 2 minutes on each side. Season with salt and pepper. Reduce the heat to medium and add the barbecue sauce. Toss to coat the tempeh in sauce. Cook for 2 minutes, adding water as needed to prevent the sauce from sticking to the pan. Remove from the heat and sprinkle with the sesame seeds. Let cool for 5 minutes.
On a work surface, lay out the bread slices. Spread the mashed avocado over 4 slices of bread and barbecue sauce over the other 4 slices. Arrange the tempeh over the mashed avocado. Top with some coleslaw and a piece of bread. Serve with the remaining coleslaw and sweet potato fries, if desired.