Mix butter, cream cheese and heavy cream together with hand mixer till blended. Add flour and salt. Do not over work the dough. Wrap in plastic wrap and refrigerate 2 to three hours till well chilled.
Roll out dough on a floured surface to 1/4 inch thickness. Using an ice cream scoop create 1" balls from the dough. Using a mini cupcake pan that has been sprayed with Pam, place each ball into a section of the pan and gently press into the bottom and sides of the pan using a wooden tool designed for this purpose. (You can find these at any kitchen store)
Once all of the dough has been used and pressed into the mini muffin tins, prepare the filling.
Combine the heavy cream and eggs until well blended. Add the swiss cheese, onions, shrimp and dill and stir to combine well.
Put 2 T of filling in each prepared curst. Sprinkle with the Parmesan Cheese.
Bake in a preheated 425º oven for 15 minutes. Reduce the heat to 350 and bake another 15 minutes.