01 - Fill a large stockpot (at least 12-quart) with water. Add Cajun seasoning, kosher salt, black peppercorns, bay leaves, paprika, hot sauce, and lemons (squeeze juice into water, then add lemon halves). Bring to a boil.
02 - Add potatoes, onions, and garlic to the pot. Boil for 10 minutes.
03 - Add corn and sausage. Continue boiling for 10 minutes more.
04 - Add crawfish to the pot. Stir well, cover, and cook for 5–7 minutes, or until crawfish shells turn bright red.
05 - Turn off the heat and stir in the butter. Let the crawfish soak in the seasoned water for an additional 10–15 minutes to absorb flavor.
06 - Using a slotted spoon, transfer crawfish, potatoes, corn, sausage, onions, and garlic to a large serving tray or directly onto a covered table.
07 - Sprinkle with extra Cajun seasoning, if desired. Serve hot.