http://www.guardian.co.uk/lifeandstyle/2012/aug/05/jose-pizarro-andalucia-spain-recipes
Original recipe uses 1kg fresh tomatoes, peeled and seeded (sieve seeds to save juice) with 340g stale country bread which is soaked with 250ml water, squeezed out before adding to tomatoes, plus 3 cloves garlic, 150ml olive oil, 2tbsp sherry vinegar, salt and a little sugar if tomatoes not very sweet.
After experiments, I recommend using whole tomatoes, quartered to remove cores, (unless you know the skins are particularly tough) about 200g bread cut into cubes and mixed with quartered tomatoes; liquidise tomatoes, bread and garlic, before adding salt, vinegar and olive oil to taste; sugar only if necessary. Proportions of bread to tomatoes dependent on juiciness of tomatoes.
Chill and serve with chopped olives and hard boiled egg, together with some crispy fried Serrano ham, all sprinkled over chilled soup.