I would make a seafood newburg. You can make the newburg sauce ahead of time and then at the last minute, you can saute the various seafood and then add the sauce. You can make a rice pilaf ahead of time and reheat or put it in a rice cooker and just turn it on 30 minutes before you need it. Alternatively, you can make toast points (very traditional, but I like it better over rice).
You can make this recipe with any combination of fresh seafood based on what is fresh and good at the market. Then just saute the seafood in butter until cooked, then add the newburg sauce and heat until bubbly and you're ready to go. I've made with flash frozen salmon, lobster, crab, shrimp and scallops...but you really can use just about any seafood and it is safe for Catholic Fridays.
http://www.epicurious.com/recipes/food/views/Lobster-Newburg-11057