In a large saucepan, heat the olive oil over medium heat until shimmering.
Add the finely diced onion and sauté for about 5 minutes, stirring frequently, until the onions become soft and translucent.
Incorporate the minced garlic into the saucepan and cook for 1 additional minute, or until it becomes fragrant, being careful not to let it burn.
Carefully pour in the crushed tomatoes and add the tomato paste, stirring to thoroughly combine all ingredients into a cohesive sauce.
Season the sauce by adding the dried oregano, dried basil, and red pepper flakes (if desired), along with a sprinkle of salt and freshly cracked black pepper to suit your taste.
Allow the mixture to come to a gentle simmer. Then, reduce the heat to low and let the sauce simmer uncovered for about 20-25 minutes, stirring occasionally to prevent sticking.
Once the sauce has thickened to your desired consistency, stir in the balsamic vinegar to enhance the flavors.
Remove the saucepan from heat and let the sauce cool slightly before tossing it with your freshly cooked ravioli.
To serve, garnish each plate with fresh basil leaves and generously sprinkle with grated Parmesan cheese for added flavor and visual appeal.