Do try the sauce as written.... it is a major contributor to the final product, especially with fire-roasted tomatoes!
This is a favorite at our house. Eventually, I started using our preferred store-bought sauce to save time (gia russa cherry tomato). It is probably the most requested dinner from our four-year-old, even above pizza! I double the recipe in an 8x8 pan, for our family of three (that four year old loves it so much, she eats as much of it as we do!) and send the leftovers to work with my husband the next day - he reports it is great reheated too. I've prepared this for dinner guests as well as send-home meals for friends recovering from surgeries and each time it gets rave reviews.
Made this with jarred sauce and it turned out great! Even though I was tempted to leave out eggplant step to hurry things along, I didn't-- and wouldn't recommend doing so. Keep an eye on it-- I should have tented some foil over it to keep it from browning too much.