Shrimp Boil with Spicy Horseradish Sauce - Waterfront Seafood

Ingredients

• 1 lemon quartered
• 5 Tbsp Cajun or Creole seasoning
• 2 ½ tsp cayenne, divided
• 1 bay leaf
• 4 garlic cloves, coarsely chopped
• 8 small boiling potatoes (about 2 inches across)
• 4 ears of corn, shucked and halved
• 1 ½ lbs large shrimp in the shell
• 1/3 cup ketchup
• 1/3 cup mayonnaise
• 1 ½ Tbsp prepared white horseradish