Preheat the oven to 350 degrees F if cooking at once. (Casserole can be assembled a day ahead and refrigerated). Lightly grease a 3-quart baking dish with melted butter and set aside.
Place the water and salt in a large saucepan and bring to a boil over medium-high heat. Slowly stir in the grits, reduce the heat to low and cover the pan. Simmer for 5 minutes, or until cooked, stirring occasionally. Remove the pan from the heat.
Stir 1 cup of the cheese and butter into grits until melted. Add eggs, milk and sausage. Pour grits mixture into the prepared pan and sprinkle with remaining cheese and pecans.
Place the pan in the oven and bake 1 hour, or until casserole bubbles and pecans have browned. Remove the pan to a rack to cool for 15 minutes before serving.
Note: To make the day ahead, cover with plastic wrap and refrigerate after topping casserole with shredded cheese and pecans. Bake as directed the next morning.