How to Make It
Preheat oven to 450°F. Toss together diced celery root and oil on a rimmed baking sheet. Bake until tender, 10 to 15 minutes.
Bring water and 1/2 teaspoon of the salt to a boil in a saucepan over medium-high. Stir in grits, and simmer, stirring, until done, 20 to 25 minutes. Remove from heat; stir in cheese.
Melt 1 tablespoon of the butter in a large skillet over medium-high. Add onion; cook, stirring occasionally, until caramelized, about 10 minutes. Add celery root, black-eyed peas, bell peppers, tomato, garlic, and 1 teaspoon of the salt; cook, stirring, until tender, 6 to 8 minutes. Add 1 cup of the stock, and cook, stirring occasionally, until liquid thickens, 20 to 25 minutes.
Melt remaining 2 tablespoons butter in a medium skillet over medium-high. Add shrimp and scallops; cook until shrimp turn pink and are almost done, 2 to 3 minutes. Add paprika, black pepper, 1 teaspoon of the hot sauce, and remaining 1/2 cup stock and 1/4 teaspoon salt; bring to a boil. Cook until shrimp and scallops are done, about 2 minutes. Transfer shrimp and scallops to a plate, and cover to keep warm. Increase heat to high, and cook stock mixture until thickened slightly, 5 to 6 minutes.
Divide cheese grits among 4 bowls. Top each with about 3/4 cup celery root mixture, 3 shrimp, 3 scallops, and a spoonful of sauce from each skillet. Sprinkle with remaining 1/2 teaspoon hot sauce.