Heat the oil in a large saute pan over medium-high heat. Add the garlic, carrots, celery and onions. Sprinkle with salt and pepper and cook about 3 minutes. Add the tomato paste, thyme and nutmeg, and continue cooking until the vegetables have softened and started to brown, about 2 minutes. Deglaze with the wine, pulling up any bits from the bottom of the pan. Season with salt and pepper.
Carefully transfer to the slow cooker. Stir in the cream and tomatoes. Mix the pork and sirloin together in a separate bowl, using your hands, until combined. Stir the meat into the slow cooker, spreading out evenly and avoiding any large clumps. Cover and cook on high for 4 to 6 hours or on low 8 to 10 hours. Skim the accumulated grease from the surface before serving. Serve over pasta with crusty bread for soaking up the sauce.