This is probably my favorite pizza that I've come up with so far. I don't actually remember if I invented it or saw it somewhere else, all I know is that it tastes great.
For the bbq chicken, I usually make my own in the crock pot during the day, and then I assemble the pizza at night. My bbq sauce is a mish-mash of ketchup, mustard (about a cup ketchup to 1/2 cup mustard), brown sugar (a lot -- about 1 and 1/2 cups packed at least), diced onions, about 1/4 cup of beer (no more, or this will be runny), a small can of tomato paste, garlic, salt, cumin, coriander, hot sauce, and a little bit of liquid smoke. Molasses also works well in there, but I don't always have it on hand, so honey will also work. I whisk that all together, then I add four or more chicken breasts. Then I drink the rest of the beer, and go to work for a few hours!
If I haven't had the time to do all that, I have also just coated leftover chicken in bottled bbq sauce (Famous Dave's is my fave) and that works just dandy.
After 6 hours on low, or 4 on high, the chicken should be loose enough to shred with a couple of forks in the pot when you get home. For this pizza, I toasted a whole-wheat crust from Trader Joe's, and then put down some pasta sauce (thinly), and piled on the bbq chicken. Then I crumbled goat cheese all around, and some long-sliced red onions. Drizzle bbq sauce over that, and then add shredded cheese. Then shake a little Italian seasoning on, and just a light drizzle of olive oil, bake at 375 until done, and be careful not to change past and present tenses as often as I have.
This pizza has a rich, deep flavor and Chris and I pretty much eat the whole thing every time!