Add the walnuts, garlic and salt and pepper to the champagne vinegar and slowly whisk in the walnut oil.
Baste the four portobello mushrooms with the vinaigrette and grill over a table top grill.
Toss the frisee and the watercress with the remaining vinaigrette and place the mushroom in the center of the plate and mound the frissee on top. Garnish with jumbo lump crabmeat
Recipe Courtesy of Jim Coleman