For the spanner crab salad, combine all the ingredients in a bowl. Refrigerate until needed.For the tomato concasse, combine all the ingredients in a bowl and set aside.
For the chilli vinaigrette, place all the ingredients in a bowl. Stir until the sugar dissolves, then set aside.
To assemble, using two tablespoons, shape the crab salad into quenelles and place in an S shape on a large white plate. Sprinkle the tomato concasse, mandarin segments, seaweed, wing beans and torn zucchini petals around the plate. Toss the cucumber in the vinaigrette, then place the slices on top of the concasse. Drizzle the whole plate with a little vinaigrette. Scatter with coconut and serve immediately.