This is one of those simple, but totally satisfactory salads. The sour apple, salty feta and sweet raisins work like a dream. Omit the bacon for a veggie version.
Heat the olive oil in a large, heavy-based frying pan over a high heat. Add the bacon and fry until crisp. Drain on kitchen paper and chop or scrunch into smaller, bite-sized pieces. Wipe the pan clean and dry-fry the walnuts over a medium heat, until just toasted. Remove and set aside.
Core and halve the apples. Cut into thin slices and then into fine matchsti