Microwave potatoes: Place diced potatoes in a microwave-safe bowl with 2 tbsp water. Cover and microwave on high for 5-7 minutes, stirring halfway, until tender. Drain and rice half of the potatoes, leaving half cubed.
4 In a cast iron skillet, melt the butter and sauté onions for 3 minutes until they begin to soften.
5 Add the garlic and anchovy paste and Herbes de Provence. Cook for an additional 45 seconds to bloom the flavors.
6 Stir in the flaked salmon and the mixed peppercorn medley. Cook for a few minutes to let the flavors meld before adding the salmon liquid, potatoes, and milk.
7 Gently stir in the cubed and riced potatoes, liquid from the salmon can, and milk. Taste and adjust for salt.
8 Let the filling cool for 10-15 minutes.
9 Fill one pie crust with the mixture.
10 Decorate the crust: After placing the second crust on top and trimming the excess, crimp the edges to seal. Roll out the extra dough and use it to cut out fish or underwater-themed decorations. Use cookie cutters and metal drinking straws to make shapes and poke holes for venting and create bubble-like circles as part of the decoration.
11 Brush egg wash onto all parts of crust
12 Bake for 45-50 minutes until the crust is golden brown.
13 Cool for 10 minutes before serving.
Prepare the salmon: Drain the canned salmon and flake it with a fork. Carefully pick out and discard as many bones as possible. Save the liquid to add to the filling mixture later.