Creamy Mushroom Puffs

Make the mushroom filling.

1. Slice the mushrooms and chop the aromatics, if you haven't already, then heat a skillet over medium-high heat. Add the oil or vegan butter, then once the oil is hot, add in the onion, garlic, sliced mushrooms, and 1/4 teaspoon of the salt. Mix well until the all the mushrooms are coated with the oil mixture. Spread evenly, and let the mushrooms sit, undisturbed, for 2 to 4 minutes, depending on your skillet and your stove. You want the mushrooms to start to brown on some of the edges. 
2. Add in the black pepper or pepper flakes, thyme, the rest of the salt, and the balsamic vinegar or wine, and mix well to deglaze the pan. If the pan is drying out too much, you can also add in a splash of water. Continue to cook this for another 2 to 3 minutes, then cover with a lid and continue to cook for 5 more minutes. Open the lid again, mix really well, and check if the mushrooms. are drying out, add a splash of water, and cover with the lid and continue to cook these until the mushrooms are just about cooked, checking in every 3 to 4 minutes. Depending on your skillet and the stove, the total time for the mushrooms to get cooked will be anywhere from 11 to 15 minutes.

Meanwhile, make the cream sauce.

1. Add all of the cream sauce ingredients to a blender, and then blend for a minute. Let the mixture sit to rehydrate the ingredients, and then blend again for half a minute, and repeat after letting the mixture sit for a minute, until the mixture is nicely smooth. If the mixture is too thick for your blender, add in another 1/4 cup of water and blend in.
2. Once the mushrooms are cooked to preference, remove about 1/3 of these mushrooms to a bowl, then add in your blended cream mixture, and reduce the heat to medium. Bring the cream to a boil, then taste and adjust salt and flavor. Add more salt, herbs, black pepper, heat, or any other flavors that you like. Then, continue to cook the cream mixture for another 2 to 3 minutes, until it thickens evenly. Switch off the heat, and let this mixture cool for 10 to 15 minutes. Then, transfer to the fridge to chill and thicken some more(15 mins or so)

Assemble the puffs.

1. Preheat the oven to 400° F (205° C). Remove the puff pastry sheets from your freezer, and put them on the counter to thaw (10-15 mins) while the mushroom cream mixture thickens in the fridge. Once they are pliable, unfold the puff pastry sheets, and then roll them out using a little bit of flour and a rolling pin. Roll it out to about 1” to 2” larger than the original size of the sheets. This helps the sheets get more flaky and puff better. Then, slice each sheet into six equal pieces each, for a total of 12 rectangles total.
2. Remove the creamy mushrooms from the fridge, and make the pastry wash by mixing the non-dairy milk and maple syrup. Brush the corners of each of the squares. Scoop out a couple of tablespoons of the mushroom mixture into each of the squares, leaving at least an inch from each side, then top the creamy  mushrooms with some of the reserved, sautéed mushrooms. Seal the pastries by bringing the diagonal corners loosely together and sealing in the middle by pressing them. The pasty wash will help the corners stick to each other. Repeat for all of the squares. 
3. Brush all of these puffs with pastry wash again, and sprinkle on your toppings. Bake for 25 to 35 minutes, depending on your oven. Check at the 25-minute mark. If they are getting nicely golden, just move the sheet around, and continue to bake for another few minutes. Remove the puffs from the oven when they have some brown spots on some of the edges. Then, garnish with fresh herbs, if you like, and serve these immediately. The creamy mushrooms inside will be bubbling, and the pastry will be crisp. See notes for make ahead and storage.