For the Jerusalem artichoke salad with mustard vinaigrette, peel the Jerusalem artichoke tubers and boil them for 7-10 minutes in lightly salted water until soft.
In the meantime, chop the mustard pickles into small cubes. Slice one-third of the tomatoes and cut the rest into medium-sized pieces. Finely chop the parsley. Cut the crab meat into pieces.
Strain the Jerusalem artichokes, let cool and cut into thin slices.
For the mustard vinaigrette, mix pepper, mustard, salt, 1 pinch of sugar and white wine vinegar. Add oil.
Mix the crabmeat, mustard pickles, tomato pieces and parsley with the Jerusalem artichoke slices and fold in the mustard vinaigrette.
Before serving, arrange the tomato slices on plates, with the salad on top. Serve the Jerusalem artichoke salad with mustard vinaigrette.