Mushroom and Leek Pie
Mushrooms and leeks are a formidable double act. Mushrooms are earthy and packed with umami,[1] while leeks—perhaps the most underrated of the allium family—are mildly sweet and aromatic.[2] This vegetarian pie features both, cooked in a rich gravy and topped with crispy pastry.
Ingredients
12 oz mushrooms, sliced
2 leeks, sliced
4 cloves garlic, minced
1 tbsp thyme leaves
2 tbsp butter
2 tbsp flour
1½ cups milk
Salt to taste
Black pepper to taste
1 sheet puff pastry
1 egg
Vegetable oil
Begin by adding your sliced mushrooms to a dry pan over medium heat. Cook the mushrooms for 10 minutes, stirring occasionally. Mushrooms have a high water content, and will water down the other flavors in the filling if added directly. Cook the mushrooms first and they will release water, which will then evaporate instead of ending up in the filling. Browning the mushrooms will also add depth of flavor to the final dish.
When the mushrooms have browned considerably and given up much of their moisture, add about 1 teaspoon vegetable oil to the pan. Give the oil about 20 seconds to heat up, then add the minced garlic, leeks, and thyme leaves to the pan. Fry the mixture for about 5 minutes, stirring occasionally, until the leeks begin to soften.
Now, we want to make a roux to thicken the gravy. Add 2 tablespoons of butter to the pot and let it melt. Then add 2 tablespoons of flour to the pot and stir the flour into the fat. Cook, stirring, until the flour is no longer raw, which should take about 2 minutes. Pour the milk into the pan and bring to a simmer, stirring continuously to dissolve the roux. Simmer for about 5 minutes and continue to stir until the filling thickens. Season to taste with salt and black pepper, then spoon the filling into oven-safe ramekins or a single large pie dish.
Depending on the size of your ramekins, you may find that this amount of filling can make more pies. It is important to let the filling cool before placing the puff pastry over it. Otherwise, the heat and steam will melt the butter in the pastry before it has a chance to rise. Let the filling in the ramekins cool for a minimum of 30 minutes before adding the pastry lid. Ideally, the filling will be close to room temperature.
Preheat the oven to 425° F. Roll out the puff pastry sheet to about ¼ inch thick, and, using an upside-down empty ramekin as a guide, cut four ramekin-shaped rounds of pastry. Save the remaining pastry for another application, or bake them alongside the pies for some extra crust. When the filling is cool, lay pastry over each ramekin, pressing down on the edges where the crust meets the ramekin. A neat crimp is not important, as the puff pastry expands.
To glaze the pastry lids, beat an egg until it forms a smooth egg wash. Brush the egg wash over the top of each pie. Using the tip of a butter knife, make several small holes of slashes in each pie, allowing steam from the filling to escape. Bake the pies for 15 minutes at 425° F. Then turn the oven down to 400° F, and bake for an additional 15-20 minutes, or until the pastry is fully puffed and golden brown. Remove the pies from the oven. Let them cool for at least 10 minutes before serving.
Substitutions
Most types of mushrooms will work well in this pie. You can also experiment with a mixture of mushrooms! If you prefer, you can substitute the leeks for onions in this recipes. If you would like to add meat to this recipe, cooked chicken and bacon both work really well with mushrooms and leeks.
[1] Mushrooms get their umami from a naturally high concentration of guanosine monophosphate.
[2] The word “leek” is derived from the Old English name for the vegetable, “leac.” “Garlic” is actually derived from the same word: “gar-leac” translates to “spear leek,” because the shape of a garlic clove resembled the head of a spear.
Recipe
Prep Time: 10 min Cook Time: 50 min Total Time: 1 hr 40 min
(+40 min inactive)
Difficulty: 2/5
Heat Sources: oven, 1 burner
Equipment: pan, ramekins, sheet pan, rolling pin, basting brush
Servings: 4
Ingredients
12 oz mushrooms, sliced
2 leeks, sliced
4 cloves garlic, minced
1 tbsp thyme leaves
2 tbsp butter
2 tbsp flour
1½ cups milk
Salt to taste
Black pepper to taste
1 sheet puff pastry
1 egg
Vegetable oil
Instructions
1. Fry mushrooms in a dry pan over medium heat for 10 minutes, stirring occasionally.
2. When the mushrooms have given up much of their moisture, add about 1 tsp vegetable oil to the pan. Give the oil a few seconds to heat up, then add the minced garlic, leeks, and thyme leaves. Cook for 5 minutes or until the leeks soften, stirring occasionally.
3. Add the butter to the pan and let it melt, then add the flour to form a roux. Stir the flour into the butter and cook for 2 minutes.
4. Add the milk to the pan and bring to a simmer, stirring continuously. Continue simmering for 5 minutes, until the filling thickens. Season with salt and black pepper to taste.
5. Spoon the filling into ramekins, and place them on a lined sheet pan. Let the filling cool for at least 30 minutes.
6. Preheat the oven to 425° F. Roll out the puff pastry to about ¼ inch thick, and cut it into the shape of your ramekins.
7. When the filling is cool, lay the pastry over the ramekins. Beat the egg to make an egg wash, and brush the egg onto the top of each pie. Using the tip of a knife, make several steam vents in each pie.
8. Bake the pies for 15 minutes at 425° F. Then decrease the heat to 400° F and bake for an additional 15 minutes, until the pies are golden brown. Remove from the oven and let the pies cool for 10 minutes before serving.
