Heat the olive oil in a pot over medium heat. Add onions and cook until they’re soft and translucent, about 5 minutes.
Add minced garlic and sauté for about 30 seconds until it smells amazing. Don’t let it burn—yes, I’ve burned garlic and cried about it too.
Stir in crushed tomatoes, oregano, basil, sugar (if using), salt, pepper, and red pepper flakes. Bring to a gentle simmer.
Reduce heat to low and simmer uncovered for 20–30 minutes, stirring occasionally. The sauce should thicken a bit and fill your kitchen with a friendly aroma.
Taste and adjust seasoning. If it tastes flat, a tiny more salt or a splash of water to loosen it up works. If it tastes too acidic, a pinch more sugar can fix it.
If you have fresh basil, stir it in at the end for a bright, green zing. If not, no worries—season to taste and serve.