Beer boiled gulf shrimp recipe

Ingredients

• 3 cans your favorite beer
• 1 onion, cut in large pieces
• 1 head garlic, cloves cut in half
• 2 tablespoons butter
• 3 tablespoons Cajun seasoning, or to taste
• 3 pounds large Gulf shrimp
• 1 lemon
• 1/4 cup chopped parsley