Chicken sure can turn out dry, can't it? Yecch!
I'm not on the Beach, but I've read a bit about it, and I definitely know about dry chicken bits.
Try cooking the pieces in stock. You'll add flavor, but no carbs/fat/calories to speak of. Stock is awesome for virtually any plan. Dice up some aromatic veggies (onions, celery, bell peppers, etc.) and brown them a bit, add your chicken pieces, let them develop a nice sear on them, then inundate the pan with some stock and let it cook down. Voila--instant "gravy" that tastes waaaay better than anything in a package.
Or borrow a trick from Indian chefs and baste the chicken with yogurt as it roasts. If you like Indian food, you could try a garam masala or tandoori spice mix with the yogurt; if it's not your cup of tea, try it with spices you prefer.
You can also try pan-sauteeing the chicken to sear, then popping it in the oven just to finish cooking. That's how I cook my steaks after my husband showed me the trick of it--that way they always come out beautifully seared on the outside, but incredibly juicy on the inside.
Are the tenders breaded (I'm guessing not, but just want to see if we're talking about the same chicken bits here)? If not, try a variation of chicken with forty cloves of garlic. Yes, it sounds like an unholy amount of garlic, but it tastes awesome and it will turn the driest, nastiest old bird into a succulent morsel of deliciousness. The recipe is very heavy on the wine, though--not sure how South Beach handles cooking with wine, so you'd want to check on that before trying it.
Same goes for coq au vin or any of its variations.
How about cooking them up in whichever way you prefer, then tearing them into bits for a chicken salad made SB-friendly? Not sure if you want to eat 'em cold, but if you do, that's one way to do it.