Heat oil in a large saucepan over medium-high heat.Add onion; cook, stirring frequently, for 5 to 6 minutes, or until onion is soft.Add garlic and tomato paste; cook, stirring constantly, for 1 minute.Add wine (alternatively you could use water or vegetable broth); cook, stirring constantly, for 1 minute.Add tomatoes, salt and pepper. Bring to a boil, stirring frequently. Reduce heat to low; gently boil, stirring occasionally for 1 hour.