Position a rack in the center of the oven and preheat to 425 degrees F. Bring a large pot of water to a boil over medium-high heat. Line a baking sheet with parchment paper.
Cut off the neck from the butternut squash. Trim the stem, then peel the neck piece. Cut the neck into quarters, standing it on the flat end as a base. With a mandoline or sharp knife, slice two of the quarters into 1/8-inch-thick strips. Save any remaining squash for another use.
Put the squash strips on the prepared baking sheet. Drizzle with 1 tablespoon of the oil and a large pinch of salt and pepper. Use your hands to rub the seasoning into the squash, and then arrange in a single layer on the baking sheet. Bake until the squash is just tender, about 15 minutes.
Heat a large Dutch oven over medium-high heat until hot, and then add 2 tablespoons of the oil. Swirl to coat, and then add the pork and a large pinch of salt and pepper. Break up the pork with a wooden spoon or rubber spatula and stir occasionally until cooked through and browned in spots, 8 to 10 minutes. Use a slotted spoon to remove the pork to a medium bowl. Add the remaining 1 tablespoon oil, the mushrooms, fennel and a pinch of salt and pepper and cook until the vegetables are tender, 6 to 8 minutes, stirring frequently and scraping up any browned bits at the bottom of the pan.
Reduce the heat to medium and add the heavy cream, Parmesan, garlic powder and a pinch of salt and pepper. Stir to combine, and then add the pork back to the pan. Bring the sauce to a gentle simmer and cook until the sauce has thickened slightly, to the consistency of a thin gravy, about 5 minutes, stirring occasionally.
While the sauce simmers, cook the egg noodles according to the package instructions. Drain the noodles and fold them into the sauce. Gently fold in half of the butternut squash until just combined, and then fold in the remaining half, being careful not to break up the squash too much. Divide into bowls and garnish with microgreens.