Add olive oil to a large pan and set over medium heat. Once heated, add diced onion and cook for approximately 6-7 minutes, then add carrot and celery then cook for another approximately 2-3 minutes. Add minced garlic, 1/2 tsp of the salt and pepper. Stir everything up and cook for another 1-2 minutes.
Add ground beef to the sauce pan and break it into crumbles. Cook for approximately 9-10 minutes, or until no pink remains and the beef is fully cooked and browned.
Once beef is cooked, pour in the red wine and scrape any browned bits from the bottom of the pan. Let everything bubble and cook for approximately 3-4 minutes.
Pour in the crushed tomatoes and add the remaining 1/4 tsp salt, parsley, basil, oregano, crushed red pepper, thyme, and a pinch of allspice. Give everything a stir, then let simmer for approximately 35-45 minutes, or until thickened to your liking. Serve over cooked spaghetti squash strands.
To prepare the spaghetti squash:
Instant Pot: Add the trivet to the Instant Pot and pour in 1 cup of water. Pierce the spaghetti squash all over with a paring knife, then place the whole spaghetti squash on the trivet inside of the Instant Pot. Close and lock the lid, and set the valve to Sealing. Cook on Manual high pressure for approximately 25 minutes. Do a quick pressure release and let the squash cool enough to be able to handle. Cut it in half, scoop out and discard seeds. Use a fork to work out the strands, then serve.
Oven: Preheat the oven to 400°F and line a baking sheet with foil or parchment paper. Trim the ends off of the squash and cut it in half lengthwise. Scoop out and remove the seeds. Place both halves of the spaghetti squash cut-side down on a baking sheet, then roast for approximately 25-30 minutes, or until the insides are tender and able to be scraped into strands.