AWESOME! I don't know what some of the other reviewers were talking about in regards to lack of flavour. I thought the flavour was wonderful.
I have made this recipe with chicken and another time with a mix of large shrimp (1.25 ilb,) and scallops (1 ilb.). I seared those seperately with a little olive oil, salt, and fresh cracked pepper and then added them in at the end. Both versions of this recipe were great.
As for changes to the recipe in general besides what type of protien I used, I could not find roasted Italian cherry peppers, so I substituted an equal amount of sliced roasted red peppers and added 1/2 tsp. crushed red chili flakes. I put the flakes in with the garlic, at the beginning, to bring out their flavour. The 1/2 tsp. was just enough to say 'hey, I'm here, I'm spice, but not too much spice'. If you wanted this dish to have more kick, I'm sure you could use a whole tsp. without overpowering the other flavours.
Also, the spaghetti sauce I used was President's Choice Marinara sauce. If you're not Canadian, you might not know this brand, but it's a groccery store brand of okay quality. It worked out great.