Start by heating the olive oil in a large saucepan over medium heat, and sauté the chopped onion until it becomes translucent and fragrant, about 5 minutes.
Add the minced garlic to the pan and cook for another minute until it releases a warm, inviting aroma.
Pour in the ripe tomatoes, breaking them apart with your spoon as they start to soften and release their juices, about 10 minutes.
Stir in the sugar, dried oregano, and season with salt and pepper, adjusting the flavors to your liking.
Pour in the balsamic vinegar, stirring well to combine, then reduce the heat to low and let the sauce simmer gently for another 15 minutes, stirring occasionally until it thickens and deepens in color.
Once the sauce has reached your desired consistency, remove from heat and let it rest for a few minutes before serving.