Crisp Mackerel Salad with Grainy-Mustard Vinaigrette

Ingredients in this Recipe

1 small garlic clove, minced
1 tablespoon chopped fresh chives
1 tablespoon chopped fresh tarragon
1 tablespoon finely chopped shallot
1 tablespoon whole grain mustard
1/2 teaspoon coarse salt
1/4 teaspoon freshly ground pepper
2 tablespoons white wine vinegar
3 tablespoons extra virgin olive oil
4 cups watercress, thick stems discarded
4 fresh Atlantic mackerel fillets (also called Boston mackerel), skin on (about 4 ounces each)
Juice of 1 lemon (about 2 tablespoons)
Vegetable oil cooking spray

See Full Recipe at Martha Stewart