Green Salad with Grapefruit and Pomegranate

Rinse lettuce and sorrel, trim, spin dry and tear into bite-sized pieces. Peel grapefruit with a sharp knife removing bitter white pith and cut between membranes to remove whole segments. Gently roll pomegranate over the work surface, then cut off the top and bottom and cut on one side. Unwrap pomegranate outwards and remove seeds. Rinse fennel, set aside leaves for garnish and thinly slice bulb. Peel onion and slice thinly. Place fennel and onion rings in a colander and scald with boiling water, rinse with cold water, drain and mix together in a bowl with grapefruit segments and pomegranate seeds. Add lettuce to the bowl, mix and arrange salad on plates. Sprinkle with fennel leaves.