Salty onion, chilli and lemon relish

Ingredients

1 medium onion; white skin is best

½ tsp chilli flakes, or to taste

juice of 1 large lemon

1 tsp salt

Preparation

Peel and halve the onion, then slice paper-thin with a very sharp kitchen knife. Take your time if your knife skills aren't great; it's important for the flavour and the texture that the onion should be sliced very thinly. Mix the four ingredients together in a small bowl. Pack them down, cover with clingfilm and place a weight on top. Refrigerate for at least 6 hours, preferably overnight. Serve chilled.