Place the wild mushrooms in a large, dry skillet. Cook them over high heat, stirring frequently, for 10 to 12 minutes. After 5 minutes, sprinkle in the salt.
Deglaze the pan with the white wine, then stir in the black pepper and fresh parsley. Cook for 3 to 4 minutes, or until the majority of the liquid has evaporated. Remove the mushrooms from the skillet and set them aside.
Place the vegan butter in the skillet, then add the shallots, carrots and celery. Cook for 10 minutes, or until the carrots have softened, then stir through the garlic.
Sprinkle in the almond flour, flaxseeds and cashews. Pour in the vegetable stock and allow the mixture to simmer over low heat for 15 minutes. Add the spinach in batches and cook until wilted, then remove the mixture from the stove.
Add in the mushrooms, and stir to combine.
Preheat your oven to 375°F (190°C). Line and grease a 14 x 6–inch (35 x 15–cm) loaf pan.
Transfer the mixture to the pan. Even it out with a spatula, pressing down firmly to neatly pack the loaf pan. Bake for 25 to 30 minutes, or until the top is nicely golden. Allow the roast to cool for 10 minutes, before carefully turning it upside down on a serving platter. Top with the parsley, if using, before slicing.