In a large kettle, bring 6 cups water to a boil; add the Crab Boil. Simmer for 10 minutes. Add the shrimp and cook for 4 to 5 minutes, until shrimp turn pink and are translucent throughout (cut one to test). Drain well.

In a small bowl, whisk together the vinegar, celery seeds, mustard, olive oil, and cayenne pepper.

In a large bowl, arrange 1/2 of the cooked shrimp. Cover with half of the onion slices and the bay leaves. Top with another layer of shrimp and onions. Pour the dressing over the shrimp, cover, and marinate in the refrigerator for 24 hours.

To serve, drain the shrimp and onions of as much oil as possible; discard the bay leaves. Place the shrimp and onions in a bowl and serve with toothpicks.

This recipe yields 10 servings.

Exchanges Per Serving: 2 Very Lean Meat

Nutrition Facts: 87 calories (23% calories from fat), 15 g protein, 3 g total fat (0.3 g saturated fat), 2 g carbohydrate, 0 dietary fiber, 135 mg cholesterol, 158 mg sodium.