Halve <quantity>1<unit>kg</unit></quantity> of tomatoes

Roughly chop <quantity>3<unit>stalks</unit></quantity> of celery

Roughly chop <quantity>1<unit>bunch</unit></quantity> of basil

Trim, peel, and quarter <quantity>1</quantity> white onion

Place all the ingredients in a blender and add <quantity>1</quantity> garlic clove

Blend until you obtain a paste consistency

Set a kitchen towel over a strainer. Pour the mixture, wrap with the towel and add some weights over it

Let it drain in the refrigerator overnight

Transfer to another recipient and season with salt to taste. The tomato water is ready