Heat oil over medium-high heat. Add the onion and mushrooms and cook for about 15 minutes, or until the vegetables are softened and start to brown. Add garlic and tomato paste and cook for one minute.
Transfer to a Crock-Pot. Stir in the crushed tomatoes, red wine, Italian seasoning, salt, and pepper. Cook over low heat for 4 to 6 hours.
Stir in the half and half and cook until warm, about 10 more minutes. Serve with zucchini noodles or gluten-free pasta.