Tomato jelly with crab and chives

Soak the gelatin leaves in cold water for five minutes. Heat the tomato juice in a small pan. Remove the gelatin and squeeze dry then add to the hot tomato juice, whisking until dissolved. Allow to cool for 15 minutes. Cut the tomatoes in half, discard seeds and juice and chop roughly. Whiz the tomatoes, shallot, vinegar, olive oil, sugar, Tabasco, sea salt and pepper until smooth. Stir the tomato juice, add to blender and mix. Taste for seasoning, pour into serving glasses, place on a tray and refrigerate overnight until set. Toss the cucumber with crab, lemon juice, salt and pepper. Add a spoonful to each jelly. Scatter with chives and serve.