*Note: Amount given for sorrel (or spinach) is for trimmed weight. Take some sorrel or spinach leaves and roll them up tightly, a few at a time. Snip across with scissors to make fine green ribbony shreds. Chop the broccoli florets into very small pieces indeed, and bring a large pan of salted water to the boil for cooking the pasta. Melt 2 oz butter in a flameproof casserole suitable for bringing to table. Add the broccoli, stir to coat with fat, cover with a lid and cook gently for just 1 minute. Add a very generous grinding of pepper, some salt and 2 teaspoons lemon juice (or quite a bit more lemon if using spinach). Shake the casserole to distribute the flavourings, then scatter the flaked fish over the broccoli but do not stir it in. Cover and leave over very gentle heat for just 3 minutes or so. Meanwhile cook the pasta. Draw the casserole away from the heat. Add the well drained pasta, the Parmesan and most of the sorrel or spinach ribbons. Toss quickly, gently and thoroughly so that every strand of pasta is anointed with butter and prettily flecked with the pink and green of the salmon and vegetables. Check the seasoning, sprinkle the remaining ribbons of greenery over the top and serve straight away, accompanied by wedges of lemon instead of the ubiquitous bowl of grated Parmesan cheese.