Tear 50g of stale bread (not sliced bread) into about 3cm pieces and put in a bowl. Leave out for an hour if not already stale. Chop up two tomatoes into chunks and finely dice half a small red onion. Add to the bread and grind over some black pepper. Spoon over one tablespoon of olive oil and three tablespoons of red wine vinegar. Mix all the ingredients together and leave for half an hour. Open a 100g can of tuna (or use 100g of canned, drained chickpeas) drain and flake and mix in with the panzanella salad and serve.