Let a cup of water boil in a pot. Put precooked shrimp in the water, and let simmer for 20 mins.  Add cajun seasoning to the water. Slice a piece of a bulb of garlic. Chop it in small pieces. Add it, and garlic powder in a bowl. Add two tablespoons of butter. Put bowl in microwave for 40 secs. Let bowl sit on counter top afterwards. Let 1 cup of water boil, then add 1/4 cup of grits add salf if you like. Let simmer on medium low heat for 7 mins. Afterwards add shrimp over grits with garlic