For the stuffing I combined equal parts (maybe a couple of Tbsp each) of full-fat cream cheese, butter, and parmesan from the green can. Then I mashed in about a Tbsp of Knorr's Alfredo sauce mix.
I took the resulting glop and, after separating the skin from the meat to make a pocket, stuffed the breasts. (I didn't think of it, but afterward I realized I could have cut slits into the meat to get the flavor even more into it.) After all 4 were stuffed, I brushed the tops with olive oil and put them into a 375º oven; because the breasts were enormous, it took them nearly an hour to get done.
But OHHHHHHH were they worth it! The meat was so juicy, and infused with the flavors of the stuffing...it was AMAZING!!!