In an extra-large stockpot or Dutch oven (about 10 quarts or larger) over medium-high heat, combine the water and beer (if using). Bring to a boil. Season with the Creole Cajun seasoning, Old Bay seasoning, and a few dashes of hot sauce, to taste. Add the sliced onion and lemon wedges. Stir well to combine. Boil for 15 minutes.

Carefully add the andouille sausage rounds and baby potatoes into the pot, stirring well to combine with the boil. Cook for 15 to 20 minutes, or until the potatoes are just about fork-tender.

Gently nestle the snow crab clusters into the pot along with the shrimp and corn on the cob. Ensure everything is fully submerged under the boil and carefully stir to combine. Continue boiling for another 5 to 7 minutes, until the shrimp is pink. Meanwhile, prepare the garlic butter sauce.

In a small saucepan over medium heat, combine the butter, garlic, lemon juice, Old Bay seasoning, parsley, Creole Cajun seasoning, smoked paprika, and hot sauce, to taste. Stir and simmer until the butter melts and the sauce is well combined, stirring often, about 5 to 7 minutes. Remove from heat.

Line an extra-large baking sheet with foil, parchment paper, or newspaper. Use a spider strainer to remove the seafood boil contents from the pot and place onto the prepared baking sheet along with the hard-boiled eggs (if using); discard the onion and lemon bits. If a thinner garlic butter sauce is desired, add some of the seafood boil broth to adjust consistency. Pour the garlic butter sauce over the seafood boil ingredients. Use hands (with disposable gloves if desired) to toss the sauce with everything, coating thoroughly.

Serve the Cajun seafood boil as-is, allowing everyone to grab from the baking sheet, or divide onto individual plates. Serve immediately with lemon wedges, if desired. Sop up any runaway garlic butter sauce. Enjoy!