Made this tonight using Fetta instead of Mozzarella. I only cooked 2 chicken breasts, but all the vegies and added broccolli as well. Delicious, and surprisingly easy. I reduced the time by 5minutes and everything was perfectly cooked. The sauce was quite nice, although I agree that it's a little thin. A good splash of white wine and some extra flour would be delicious.
I was worried that everything would be cold by the time the sauce had finished cooking, but I plated up, removing toothpicks etc, and the sauce was finished at exactly the right time.
Could definitely vary the stuffing to almost anything, and with different vegies, maybe pasta instead of potato.
I used the leftover stuffing in my Swirly Spinach and Fetta Rolls - now with added capsicum and zucchini.
Huge thumbs up!