Combine the water and grits in a medium saucepan. Place over medium-high heat and whisk constantly until the starches thicken and it begins to bubble, so as to avoid lumps. This will take about 10 minutes. Once they are thick and gently simmering, turn the heat to low and place a lid on top to help with splatters, leaving it slightly ajar to allow steam to release. Cook, stirring occasionally, for 30-40 minutes on low heat. When the grits are soft and creamy, add the butter and a half teaspoon of salt and freshly cracked black pepper to taste. Taste and add more salt if needed. Take off the heat and stir in the cheese. Cover with the lid and leave while you cook the shrimp and sausage.
In a medium skillet, warm the olive oil. Squeeze the sausage meat out of the casing and into balls about the size of walnuts (it's ok if they are not all uniform). Cook in the skillet, stirring and shaking the pan, until cooked through. Add the shrimp, garlic and paprika, and ½ teaspoon salt. Cook until the shrimp are pink, then stir in the butter. After the butter is melted, remove from the heat and squeeze the lemon juice over top.
To serve, scoop the grits onto a large serving platter, or individual bowls. Top with the shrimp and sausage mixture, and sprinkle with the parsley.