Prepare the base
Heat the oil in a large Dutch oven over medium heat. Add the finely chopped onion and cook, stirring occasionally, for about 3 minutes, or until the onion becomes soft. Then, add the carrot and celery and continue cooking for an additional 5 minutes, stirring occasionally. Incorporate the garlic, ginger, and tomato paste, allowing the mixture to caramelize for 2-3 minutes. Adjust the heat as necessary to prevent burning, then return the heat to medium.
Cook the beef and mushrooms
Add the ground beef, mushrooms, and half of the scallions to the pan. Stir the mixture to break up the beef and cook until the beef is browned, approximately 3-4 minutes. Next, pour in the soy sauce, turbinado sugar, and ¼ cup of water. Bring the mixture to a simmer, then cover and reduce the heat. Let it simmer gently on low heat, stirring occasionally, for about 30 minutes until the sauce thickens. Once the sauce has reached the desired consistency, stir in the remaining scallions and season with kosher salt and black pepper to taste.
Cook the pasta
While the sauce simmers, bring a large pot of salted water to a boil. Cook the pasta according to the package directions until it reaches an al dente texture. Drain the pasta and set it aside.
Assemble the dish
Divide the pasta into individual bowls, and top generously with the prepared Bolognese sauce. Serve with a sprinkle of freshly grated Parmesan for added richness and flavor.