Wash the tomatoes thoroughly to remove any dirt or debris.

Cut an "X" at the bottom of each tomato, then blanch them in boiling water for about 30 seconds.

Transfer the blanched tomatoes to an ice bath immediately to stop the cooking process.

Once cool, peel the skins off the tomatoes and discard the skins.

Add the peeled tomatoes, olive oil, and salt to a large pot over medium heat and cook for about 15 minutes, stirring occasionally, until the tomatoes start breaking down.

Use a blender or food mill to puree the cooked tomatoes until smooth.

Return the pureed tomatoes to the pot and let simmer for at least 30 minutes to deepen the flavors.

Pour the hot Passata into sterilized jars, seal, and allow to cool before storing.