In a large skillet or dutch oven, place olive oil and onions over medium-low heat. Season with salt and pepper.
Cook until onions are translucent in color. Be careful not to burn and stir frequently.
Stir in red wine.
Stir in crushed tomatoes. Add about a tablespoon of water to each can and swish around to get all the tomatoes out.
Stir in the salt, pepper, sugar, and chopped basil.
Cover with the lid tilted a little and cook on the lowest temperature for 3 ½ to 4 hours, stirring every 15-20 minutes to ensure nothing is sticking.
After 3 ½ hours taste it and re-season if needed. The tomatoes will take on a deep sweet flavor. You can judge at this point if you think it needs to go longer.
Serve over pasta or use in your favorite Italian dish!
Store sauce in air tight container in the refrigerator for about 3 days or store properly in the freezer for 4 or 5 months.
Goes perfect with Crusty Artisan Bread !