Chilled zucchini, pea and buttermilk soup

1.Heat oil in a large saucepan over medium-high heat, add spring onion and garlic and sauté until tender (2-3 minutes). Add grated zucchini and lemon rind and sauté until zucchini softens (1-2 minutes), then add stock and peas, season to taste, bring to a simmer and cook until peas are bright green and just tender (1-2 minutes).

2.Remove from heat, cool, then add buttermilk and process in a blender or with a hand-held blender until very smooth, adding a little extra buttermilk if necessary. Add mint and blend to combine. Refrigerate to chill (3-4 hours), then stir in lemon juice, divide among chilled bowls, top with trout, sliced zucchini, extra lemon rind, radish sprouts and a drizzle of buttermilk, and serve.