Gently heat the 2 tablespoons olive oil in a large saucepan or Dutch oven over medium-low heat. Add the minced 1 large garlic clove and sauté until it turns a light golden brown (about 1-2 minutes). Watch carefully to prevent the garlic from burning, which will make the sauce bitter.
Add the finely chopped 1/2 onion and cook, stirring frequently, until it becomes soft and translucent (5-7 minutes). Stir in the 1 teaspoon dried basil, 1 teaspoon dried parsley, 1/2 teaspoon freshly-ground black pepper, 1/2 teaspoon dried oregano, and 1 teaspoon salt. Next, add the 28 ounces crushed tomatoes, 29 ounces tomato puree and 4 tablespoons sugar. Increase the heat to medium-high and bring the sauce slowly to a full boil. Once boiling, cover the pot and let it cook vigorously for 10 minutes.
Reduce the heat to the lowest setting (it should maintain a gentle simmer). Cover the pot loosely and allow the sauce to simmer for at least 1 hour, stirring occasionally. This long simmer time is essential for developing the deep, sweet, and comforting flavor characteristic of Prego.
After simmering, taste and adjust any final seasonings. This recipe yields approximately 6 cups of finished spaghetti sauce, perfect for immediate use or freezing for future meals.