Set your pressure cooker pot to the high saute setting.
Melt the butter. Add onion, carrot and celery, and cook, stirring often, until onions have become translucent, about 3-4 minutes.
Add the ground beef, pork, pancetta, 1 teaspoon salt and 1/2 teaspoon pepper, and cook until browned, about 5-10 minutes. (Be sure to crumble the beef and pork as it cooks; drain excess fat.)
Stir in tomato paste, garlic, Italian seasoning, red pepper flakes, nutmeg and cinnamon until fragrant, about 1 minute.
Stir in wine, scraping any browned bits from the bottom of the pot, and cook until reduced, about 2 minutes.
Stir in crushed tomatoes and beef stock.
Select manual setting; adjust pressure to high, and set time for 20 minutes. When finished cooking, quick-release pressure according to manufacturer’s directions.
Select low sauté setting; simmer, uncovered, stirring often, until thickened to desired consistency, about 5-10 minutes. Stir in heavy cream and parsley; season with salt and pepper, to taste.
Serve immediately. Ideally, we like a wide noodle pasta, such as Pappardelle. We've also served this over Potato Gnocchi. This sauce freezes well.