My go-to cold "soup" as a summer starter is salmorejo, a sort of thicker version of gazpacho from Andalucía. It's made with puréed tomatoes, stale bread, olive oil and garlic. You serve it in small glasses with crumbled hard-boiled egg and little chunks of Serrano ham scattered on top and a little breadstick or two on the side. Contrary to received wisdom, you can make it with good quality canned plum tomatoes. Also, contrary to received wisdom, you can blitz fresh tomatoes if that's what you're using without bothering to skin them first. The secret ingredient for any Mediterranean tomato-based dish is half a teaspoon of sugar.