The filling is a good basic recipe that can be expanded upon. I used aged asiago cheese & imitation crab meat that I wanted to use up, fresh tomatoes, red onions and Ritz instead of bread crumbs. Next time I will try different veggies, canned salmon, etc. Also I plan to add some parmesan cheese to the Ritz, & put the mushrooms under the broiler for added crunch to the crackers. Plus, instead of the dry Italian dressing, I may try dry ranch dressing. Yummy!