To make the Bolognese: While the squash is baking make the Bolognese sauce. In a large bowl mix together the pork and beef and season with 1 tablespoon kosher salt. Continue to lightly mix until the meat is combined and evenly seasoned.
In a large, high-sided sauté pan or Dutch oven over high heat add the olive oil. When the oil is smoking, add the pork and beef mixture in batches to the hot pan and cook until the meat is seared on all sides. Remove the seared meat to a paper towel lined sheet tray, leaving behind any rendered fat in the pan, and continue to sear the remaining meat in batches, ensuring that you do not overcrowd the pan and steam the meat. Set the seared meat aside.
In the same pan, over medium heat, add the onion and cook 5 minutes or until beginning to caramelize. Then add in the carrots, celery, 1 teaspoon kosher salt, garlic, parsley, sage and 1/4 cup basil. Cook for 5-6 minutes or until the vegetables are soft and just beginning to caramelize. Add the meat back to the pan along with the crushed tomatoes and beef broth. Bring the mixture to a boil and reduce to a simmer, stirring occasionally. Season with additional kosher salt to taste and crushed red pepper flakes. Continue to simmer for at least 1 hour or until the sauce has thickened. You can continue to cook the sauce for longer, if you have time; the longer you cook the sauce the deeper the flavor. While the sauce simmers roast the spaghetti squash.
To make the spaghetti squash: Preheat oven to 425 degrees F.
Cut the squash in half lengthwise and discard the seeds. Season each squash half with 1 tablespoon olive oil, 1 teaspoon kosher salt and 1/4 teaspoon crushed red pepper. Add two large basil leaves to the cavity of each squash and then turn the squash cavity side down on a half sheet tray. You will need two half sheet trays to hold all six halves. Roast the squash for 40 minutes or until the squash is fork tender and easily shreds when you run a fork over the flesh. Remove from oven and let cool 10-15 minutes.
When the squash is cool enough to handle scoop the squash away from the skin and place back on the sheet tray. You can discard the squash skin at this point. Spread the squash evenly on the sheet tray and shred it lightly with a fork so it looks like spaghetti. Place the sheet trays back in the oven and cook an additional 15 minutes or until the excess liquid has evaporated and the squash has just begun to crisp and lightly brown. Remove from the oven and let cool slightly. Drizzle with extra virgin olive oil and season with flaky sea salt.
To serve: When ready to serve, stir in the remaining basil and vinegar to the Bolognese sauce. Taste and add additional seasoning as necessary.
Add spaghetti squash to a serving bowl and top with the sage and basil Bolognese sauce. Serve each portion with a 1/4 cup of cashew ricotta, fresh sage leaves, crushed red pepper and a drizzle of extra virgin olive oil.