In a large skillet over medium-high heat warm the olive oil. When hot stir in the green pepper, mushrooms, onion, and garlic. Cook until vegetables are tender, and onions are caramelized, about 5 - 8 minutes.
Add wine to the vegetables scraping the sides and bottoms removing the bits and pieces from the pan. Stir frequently until the wine is reduced to 3/4 cup, about 10 minutes.
Add the tomatoes to the skillet and break down using the back of a wooden spoon repeating occasionally throughout the simmering. Bring to a low boil. Reduce heat to medium-low and simmer for two hours.
Add the spaghetti seasoning, salt and pepper to the sauce and continue simmering for another 30 minutes.
This robust sauce is bursting with flavor. We often serve it without meat, but it pairs perfectly with Sweet Italian Sausage or prosciutto.