If using store-bought pie crusts, check the label for instructions, as they often need to come to room temperature before rolling out.
Bring some water to a boil in a small pot. Add the quartered potatoes and 1 teaspoon kosher salt. Boil for 5-7 minutes, until a paring knife can easily be inserted into the potatoes. Drain the potatoes and cool slightly.
Once the potatoes are cool enough to handle, cut them into 1/2" (1 cm) pieces.
Add the cut potatoes to a large bowl with 1 cup frozen corn, the diced bell pepper, the minced shallot, 1/2 cup packed shredded cheddar cheese, and the thawed seafood. Set aside. Sprinkle with 1 Tablespoon cornstarch and toss again to distribute the cornstarch.
In a large measuring cup, or immersion blender vessel, blend together 1/2 cup cottage cheese, 1 Tablespoon cream, 1 Tablespoon lemon juice, 1 Tablespoon minced fresh parsley, 1 teaspoon dried savory, 1/2 teaspoon freshly ground black pepper, and the remaining 1/2 teaspoon kosher salt until combined, and the cottage cheese is smooth. Alternatively, you could use a small food processor.
Pour the cottage cheese mixture over the vegetable and seafood mixture and stir to combine.
Roll out one of the pie crusts into a 9" deep dish pie pan or a 9" round cake pan. Spread the seafood filling into the pie crust. Roll out the second pie crust and place it over the top of the filling. Crimp the two crusts together (using a fork is the simplest).
Use a fork to whisk together 1 egg and 1 Tablespoon milk. Lightly brush the top of the pie crust with some of the mixture, being sure not to put it on so heavily that there are pools of egg. (You will have egg wash leftover - you could save it for baking or scrambled eggs, if desired). Use a paring knife to cut vents into the top of the pie crust.
Heat the oven to 350°F. Place the pie onto a baking sheet to catch any leaks if they occur, and bake the pie for 40-50 minutes, or until the crust is golden brown and the filling is bubbling. (Note that if you use a glass pie pan, you may need to extend the cooking time). Allow the pie to cool for at least 10 minutes before cutting.