Shrimp with Cheddar-Parmesan Grits

In a medium bowl, mix shrimp, 2 tablespoons olive oil, paprika, cayenne pepper, 1 teaspoon salt, and pinch of black pepper to coat shrimp. Cover and refrigerate while making stock and grits.

In a medium saucepan, heat oil and butter over medium heat. Add shrimp shells, onion, leek, celery, carrot, fennel, garlic, thyme, bay leaf, and coriander. Cook without stirring, until lightly browned on bottom, about 5 minutes. Add 6 cups of water, white wine, and tomato paste. Bring to a boil, then reduce heat and simmer for flavors to meld, 45 minutes to 1 hour. Strain through a sieve, pressing solids to extract as much liquid as possible.

Bring chicken stock, milk and salt to a boil in a large, heavy-bottomed saucepan over medium-high heat. Gradually whisk in grits. Reduce heat to low and cover grits. Cook, whisking every 3 to 4 minutes to prevent grits from sticking or forming lumps, making sure to get into corners of pot when whisking, until creamy and tender, 20 to 25 minutes. Season with salt. Whisk in both cheeses. Remove from heat and let cheese melt into grits. Add butter and white pepper, if using. Whisk until butter is melted.

In a large skillet, heat remaining 2 tablespoons olive oil over medium-high. Add shrimp to skillet in an even layer and let cook without stirring for 1 to 2 minutes. Add the celery, shallots, and pimentos. Stir shrimp and return to an even layer, cooked side up. Add wine and butter and stir until butter is completely melted. Season with salt and pepper and stir in lemon juice.

Divide grits evenly between 4 to 5 serving bowls; top with shrimp and vegetables, and a spoonful of the shellfish stock. Garnish with parsley, celery leaves, and scallions.