In a large pot of water over high heat, add salt and bring to a boil. Add the package of macaroni and bring back to a boil. Continue cooking until the noodles are fully cooked. Pour off 2 cups of the starchy pasta water for later use. Drain the noodles into a colander and reserve for later use.
In a large skillet over medium-high heat, add 1 stick of butter. When the butter begins to sizzle, add the onions, celery, and green onion tops. Cook until the onions turn translucent and add the parsley. Stir the mixture and sprinkle the flour and continue cooking to make a light blond roux. Add the milk and stir to incorporate until the mixture thickens. Add only enough of the macaroni noodles to evenly balance the cream mixture and reserve the rest.
In a small bowl, add the cream and the egg. Whisk the egg into the cream and add to the pot and stir. Add the cream cheese, Parmesan, and Monterey Jack. Stir until the cheeses begin to melt and thicken the mixture. Season with salt, pepper, and a dash of hot sauce to taste. Add the shrimp and crabmeat and stir.
If needed, add more of the macaroni noodles. If the mixture is too thick, add a little of the reserved pasta water until it reaches a moist thickness. Grease a medium-sized casserole dish with ½ stick butter. Pour in the noodle mixture. Sprinkle the top with 1 ½ cups of Cheddar cheese and spread out to cover the mixture. Spread the crumbled potato chips evenly across the top and then sprinkle with the remaining ½ cup of Cheddar cheese.
Place the casserole on a baking sheet and move to the heated oven. Bake for 40 minutes or until the mixture has set and the top just begins to brown. Watch carefully in the last 10 minutes of baking and use the broiler if needed to achieve a gratin on the top.
For serving, move the casserole to the center of the table and spoon onto individual plates or bowls. Serve with a simple side salad and garlic bread.
I like the fun of using potato chips for my crust, but bread crumbs will work. Seafood options are endless in this recipe so use whatever is freshest and available.
Recipe by Acadiana Table at /2014/08/11/baked-seafood-mac-and-cheese-casserole/