Begin by filling a large pot with water and bringing it to a rolling boil over high heat. Add beer, Cajun seasoning, and Old Bay seasoning, stirring well.

Add quartered potatoes and sliced andouille sausage to the boiling broth. Cook for about 10–15 minutes or until the potatoes are tender.

Incorporate corn on the cob pieces and jumbo shrimp into the pot. Continue boiling for an additional 5–7 minutes until shrimp are opaque.

Melt unsalted butter in a saucepan over medium heat. Add minced garlic and sauté until fragrant, about 1-2 minutes; stir in Cajun seasoning.

Drain the seafood boil and pour garlic butter sauce over. Toss everything to coat with the sauce and serve immediately.