Bring water to a boil and season with salt and pepper. Add grits and cook until water is absorbed, about 20 to 25 minutes. Remove from heat and stir in three tablespoons butter and cheese.If using frozen shrimp, defrost according to package directions. If using fresh shrimp, rinse and pat dry. Add the remaining two tablespoons of butter to a skillet and melt over medium heat, then add shrimp. Cook until shrimp turn pink. Add lemon juice, parsley and garlic. Saute for 3-5 minutes or until mixture is fully coated.Spoon grits into a serving bowl. Add shrimp mixture and mix well. Serve immediately