Remove the tomato stems and make shallow cross cuts on the opposite side. Mince the onion, chop the basil, and finely mince the garlic after removing its core.

Boil water in a pot and blanch each tomato for 20 seconds using a ladle. Once the skin starts peeling, transfer to cold water and remove the skin. Roughly chop the tomatoes.

Heat olive oil in a pan over medium-low heat. Add garlic and onion, sauté until the onion becomes translucent.

Add the chopped tomatoes to the pan, stir, cover, and simmer on low heat for 7–8 minutes.

Uncover the pan, increase to medium heat, and stir for 3–4 minutes to evaporate excess liquid.

Season with salt and pepper to taste.