Start by cooking the wild rice: drain and rinse the soaked rice well, place in a pot. Add 3 cups / 750ml of fresh water, a couple pinches of sea salt, then bring to a boil, and reduce to simmer. Cook until rice is chewy-tender – about 45 minutes.
While the rice is cooking, preheat the oven to 350°F / 180°C. Spread the walnuts in a single layer on a rimmed baking sheet. Toast for 7 to 10 minutes, watching them carefully so they do not burn, until they are golden and fragrant. Remove from the oven and let cool slightly.
Turn the oven heat up to 400°F / 200°C. Give the butternut squash a good scrub, making sure to remove any dust or dirt. Leaving the skin on, slice the squash neck into rounds about 1” / 2.5cm thick. Place on a baking sheet, sprinkle with a little salt, and roast in the oven for 20-30 minutes, flipping once halfway through cooking, until the squash is fork tender. Remove from the oven and drizzle with olive oil and a little more salt, if desired.
While the squash is roasting, make the Toasted Walnut Sauce. Place the toasted walnuts, garlic, olive oil, apple cider vinegar, and maple syrup in a blender.
Blend on high, adding up to 1 cup / 250ml of water to thin the dressing as needed—you are looking for the consistency of melted ice cream. Season with salt. Store in an airtight glass container in the fridge for up to 5 days.
Lastly, prepare the mushrooms. Clean and cut the mushrooms as desired (I used king oyster mushrooms, sliced in half lengthwise and scored diagonally). Add a knob of your favourite cooking fat to a large skillet, and once melted add the mushrooms and a couple pinches of salt. Cook the mushrooms without crowding them, and do not move them about in the pan too much. You’re looking for a nice sear and that comes after the mushrooms have been in constant, direct contact with high heat. Once golden on one side, flip, and continue cooking until golden on the other.
In a large bowl, combine the wild rice and parsley. Drizzle a touch of the sauce and about ½ Tbsp. of the sumac, a few grinds of black pepper, and fold to incorporate.
To assemble, drizzle or puddle some sauce on the bottom of your serving plate. Add a round of butternut squash, followed by the wild rice mixture, a couple mushrooms, then repeat the layers of squash, rice, mushrooms. Drizzle remaining sauce over top, sprinkle with additional sumac and black pepper, and a handful of walnuts.
Say thank you and enjoy each bite, each grain.