Savory Shrimp Pie With Vegetables

1. Put the diced potato in a saucepan and cover with water. Add about 1/4 teaspoon of salt. Bring to a boil. Cover and reduce the heat to medium-low. Cook just until the potato is tender, about 5 minutes. Drain and set aside to cool.

2. Melt 3 tablespoons of the butter in a skillet or saute pan over medium-low heat. When the butter is hot, saute the mushrooms and onion until the mushrooms are tender and the onion is translucent, or about 5 to 8 minutes. Stir in shrimp and remove from the heat.

3. Meanwhile, make a white sauce. In a saucepan over medium-low heat, melt remaining 3 tablespoons butter; stir in flour, 1 teaspoon salt, and pepper. Cook for 1 minute, while whisking constantly. Gradually add milk, whisking constantly. Add the sherry, if using. Continue to cook, stirring, until thickened.

4. With a slotted spoon, add the shrimp and mushroom mixture to the sauce along with the cubed cooked potatoes, the parsley, and the cooked peas and carrots. Add more liquid from cooking the mushrooms, as needed, to thin the sauce to desired consistency. Taste and adjust seasonings.

5. Spoon the shrimp mixture into a 1-quart baking dish (an 8-inch round layer cake pan or 9-inch pie plate).  Set aside.

6. Heat the oven to 425 F.

7. Roll out the pastry to about 11 inches in diameter. Fit the pastry over the shrimp filling. Trim and tuck the overhang under; flute as desired.

8. Combine the egg white with 2 teaspoons of water and whisk to blend.

9. Brush the pastry lightly with the egg wash mixture and then sprinkle with sesame seeds, if using.

10. With a sharp knife, cut several vents in the top of the crust to let steam escape.

11. Bake in the preheated oven for 20 to 25 minutes or until the crust is nicely browned and the filling is bubbly. 

*To cook the shrimp, first peel and devein them. Put the shrimp in boiling water and cook for 1 to 3 minutes or until they are pink and just becoming opaque. Do not overcook or they will be tough.