In a heavy saucepan, bring 4 cups water to a boil. Add 1 tablespoon butter and 1/4 teaspoon salt. Stir in the grits. Lower the heat, cover and simmer, stirring frequently, until tender, about 1 hour. Stir in the cream and 1 tablespoon butter.
Meanwhile, in a skillet, heat 1 1/2 teaspoons butter over medium-high heat. Add the kielbasa and ham and cook until golden, 3 minutes; transfer to a plate. Melt 1 1/2 teaspoons butter in the skillet, add half the scallops and shrimp and cook, turning once, for 3 minutes; transfer to the plate. Repeat with 1 1/2 teaspoons butter and the remaining scallops and shrimp.
Add the remaining 1 1/2 teaspoons butter to the skillet. Add the tomatoes, garlic, scallions, cajun seasoning and 1/4 cup water and cook until softened. Stir in the reserved seafood and meat and cook until heated through; season with salt and pepper. Serve the grits topped with the seafood-meat mixture
