Preheat the oven to 350° F.
Spray a 9×13-inch baking pan with nonstick spray. Set aside.
In a skillet, cook sausage until no longer pink. Drain excess grease and set it aside.
While the sausage is cooking, make the grits. Bring water to a boil in a large saucepan, then add 1 cup of heavy cream. Bring back to a boil and slowly whisk in grits and seasonings. Whisk well for about a minute. Reduce heat to low; cook covered for 5 to 7 minutes, whisking every few minutes. Cook until thickened. Whisk well to break up any lumps. Remove from heat.
Add butter, cream cheese, Velveeta cheese, Rotel tomatoes, sausage, and 1/2 cup of heavy cream to the grits. Stir until mostly melted and mixed.
Slowly stir in eggs until blended.
Transfer to the prepared casserole dish.
Bake, uncovered, for 40 to 45 minutes.