Place 2 ring molds, about 3 to 4 inches each, in the center of 2 salad plates. Arrange the watercress around the molds.
To make the dressing, in a small bowl, whisk together the mustard, vinegar, and salt. Slowly add the olive oil, whisking constantly, until emulsified. Add the shallots, parsley and thyme and whisk until well incorporated.
In a bowl, toss the tomatoes with 1 tablespoon of the dressing and 1 teaspoon of the chives. Using a spoon, divide the tomatoes between the ring molds. Repeat the process with the cucumber, hearts of palm, artichoke hearts, and crabmeat, packing each layer down with the back of a spoon.
Carefully remove the molds and drizzle dressing over the watercress. Serve with toasted French bread croutons.
Yield: 2 servings