Remove the top stem area of the tomato and cut tomatoes in half (not from top to bottom but across the middle to expose the seed pockets (see photo above). Remove tomato seeds and place in a mesh strainer over a bowl. This will remove the liquid which will be added into the soup later.
Chop tomatoes, cucumber, pepper, and onion into large chunks. If using any vegetables for garnish, chop them into a small dice and reserve.
Peel garlic and chop into a few pieces.
Place vegetables into a blender (you may need to do this in 2 to 3 batches) and blend until smooth. Pour into a large bowl and add sherry vinegar, olive oil, drained tomato juice from seeds, and salt. Stir to combine. Taste and add more salt and/or vinegar as needed to suit your own taste.
Cover and chill overnight in the refrigerator. I usually keep mine in a juice jug so it’s easy to pour into dishes later. Stir before serving and top with your favourite garnishes.