Pat the shrimp dry with paper towels then place in a bowl. Season generously with salt and pepper.
Heat a large pan over high heat then add the butter and shrimp. Cook until they shrimp are opaque and starting to brown. Remove from the pan and set aside.
In the same pan, add another teaspoon of butter then add the garlic and the cajun seasoning.
Pour the cream into the pan along with the lemon juice. Bring up to a simmer and cook for 5 minutes until the sauce has reduced and coats the back of a spoon easily.
Add the shrimp back into the pan then allow to heat through for 1-2 minutes. Scatter over the parsley and serve.