Cheesy (and totally dairy-free!) potato and onion filling is baked up between layers of flaky puff pastry crust to make this scrumptious vegan spin on classic cheese and onion pie!
Bring a medium pot of salted water to a boil and add the potato. Boil the potato until fork tender, about 10 minutes.
When the potatoes have finished cooking, drain them into a colander and return them to the pot.
While the potatoes boil, coat the bottom of a medium skillet with 2 tablespoons of oil and place it over medium low heat. Give the oil a minute to heat up, then add the onions.
Cook the onions for 15 to 20 minutes, stirring occasionally, until they are soft and just beginning to brown.
Raise the heat to medium, add the garlic and continue cooking for about 1 minute, until the garlic becomes very fragrant.
Being to sprinkle in the flour, a bit at a time, stirring to form a paste that coats the onions. Continue cooking and stirring for about a minute after adding the last of the flour.
Begin pouring in the coconut milk, a bit at a time, and whisking it in to blend it with the flour.
After all of the coconut milk has been added, stir in the nutritional yeast, mustard and hot sauce.
Spoon a bit of the sauce out into a small cup and whisk it together with the miso until smooth. Add the mixture to the skillet and whisk to combine.
Let the sauce simmer for 3 to 4 minutes, until very thick.
Remove the skillet from the heat and stir in the potato. Season the mixture with salt and pepper to taste.
Preheat the oven to 375°F.
Lightly oil the bottom of a 9-inch deep dish pie plate*.
Roll one of your puff pastry sheets until it's large enough to cover the bottom and sides of your pie plate. Drape it into the pie plate and use a fork to poke a few holes in the bottom.
Spoon the filing into the pie plate.
Roll the second puff pastry sheet until it's large enough to cover the top of the pie. Drape it over the pie.
Trim any excess pastry around the edges, then firmly pinch the top and bottom sheets together to form a seal.
Use a knife to cut a few slits in the top of the pie, then brush it with about 1 tablespoon of olive oil.
Place the pie into the oven and bake it until the top crust is flaky and beginning to brown, about 30 to 35 minutes.
Remove the pie from the oven and let it sit for at least 10 minutes before serving. You can slice it hot, in which case it will be a bit sloppy, or let it cool a bit to firm up.
If you don't have a deep dish pie plate, a small casserole dish (about 1.7 quarts) can be used.