Serves 6 to 8

3 ounce bag shrimp or crab boil
3 tablespoons Old Bay Seasoning
2 yellow onions, peeled and quartered
3 pounds small new potatoes
5 ears corn, husked and cut in 1-1/2 to 3-inch pieces
2 pounds spicy smoked link sausage (kielbasa or andouille), diagonally sliced in 2-inch pieces
4 pounds medium to large unpeeled, deveined shrimp  
6 lemons, halved
1 bunch Italian (flat-leaf) parsley, rough chopped
Garlic Mayonnaise & Cocktail Sauce, for dipping (see recipe)  

In a 12 to 16-quart pot bring 2 gallons water to boiling. Add shrimp or crab boil and Old Bay Seasoning along with the onions and 2 lemons; reduce heat. Simmer, uncovered, 10 minutes. Add potatoes, a few at a time, allowing water to continue simmering. Simmer 7 to 10 minutes, until nearly tender. Add corn; simmer, uncovered, 5 minutes. Add sausage and shrimp. Simmer 3 to 5 minutes, until shrimp are opaque (do not overcook shrimp) and sausage is heated through; drain.

Transfer to large platter. Add remaining lemon halves and shower with parsley. Serve hot or within 1 hour of cooking. Pass Garlic Mayonnaise and Cocktail Sauce for dipping.