Servings: 16 buns
Time:

Ingredients

Potato Layer
1 1/2- 2 lbs. peeled red potatoes
cut into even halves or quarters
8 Tbsp. salted butter
1/3 cup whole milk
1/2 tsp. salt
1/2 tsp. ground black pepper
1 cup grated Parmesan cheese, plus
more for top
1⁄2 cup heavy cream (optional)

Mushroom Filling
1 lb. maitake (Grifola frondosa),
coarsely chopped into 1⁄2” pieces
1/2 lb. lion’s mane (Hericium sp.)
gently pulled apart
3 Tbsp. olive oil
1 cup finely chopped yellow onion
1/2 cup chopped fresh parsley, plus more
for serving
1/2 tsp. kosher salt
1/2 tsp. ground black pepper
A pinch of ground cumin
1 Tbsp. Worcestershire sauce
3 garlic cloves, minced

Directions

Step 1 - Preheat oven to 400°F. Place the peeled potatoes in a large pot and cover with water, add a few large pinches of salt. Bring the water to a boil and cook until potatoes are fork tender, 10–15 minutes.

Step 2 - While the water boils, make the mushroom filling. Add the oil to a large pan and heat over medium-high heat for 1 minute. Add the onion and cook for 5 minutes, stirring occasionally, until translucent.

Step 3 - Add the mushrooms and gently mix in the garlic and onion with a wooden spoon. Add the parsley, cumin, salt, pepper, and Worcestershire sauce and stir well. Cook for 8–10 minutes, stirring, until the mushrooms are browned and soft but not mushy.

Step 4 - Add the garlic, gently stir to combine, and cook for another minute. Bring the mix to a firm simmer for 5 minutes stirring occasionally. Set the mushroom
filling aside.

Step 5 - When the potatoes are cooked, drain very well in a colander and return to the hot pot. Add the butter, milk, salt, and pepper. Mash with apotato masher until smooth. Add 1 cup grated Parmesan cheese to the potatoes and stir until well combined. Add the optional 1⁄2 cup of cream if you like and stir well.

Step 6 - Spread the mushroom filling in an even layer across the bottom of a 7x11 inch baking dish. Carefully put the mashed potatoes on top of the mushroom filling and spread into an even layer. Make a wave pattern with the back of a wooden spoon.

Step 7 - Place dish on a baking sheet to avoid any dripping. Bake uncovered for 30–40 minutes making sure the potato turns slightly golden in color on the top, adding Parmesan a few minutes before taking it out for a crispy topping. Cool for 10 minutes and sprinkle more chopped fresh parsley on top before serving.