Step 1In a large pot heated over high heat, add the vegetable oil and shrimp shells. Saute until the shells turn pink, 1 to 2 minutes.
Step 2Stir in the onion, celery and carrot and continue to saute, stirring frequently, for 1 to 2 minutes. Stir in the bay leaf, peppercorns, thyme and tomato paste and continue to saute until the herbs are aromatic and the vegetables are somewhat softened, 3 to 5 minutes.
Step 3Remove the pan from heat momentarily and stir in one cup of wine, scraping any flavoring from the base of the pan. Cook, stirring frequently, until the wine evaporates, 6 to 8 minutes. Do the same with the second cup of wine. Add the water and simmer for 10 minutes, then set aside to cool before straining.
Step 4Discard the solids and refrigerate until needed. This makes a generous quart stock, more than is needed for the remainder of the recipe; the stock will keep, covered and refrigerated, up to one week.
Step 1In a medium, heavy-bottom pan, bring the cream, milk and water to a simmer over medium-high heat. Reduce the heat to low, stir in the grits and 1 teaspoon salt. Gently simmer, stirring frequently (to prevent the grits from sticking to the bottom of the pan), until the grits are tender and thickened, 45 minutes to 1 hour; the grits should have a pudding-like consistency. Add additional milk or water as needed to keep the grits moist while cooking; depending on the age, type and brand, some grits will require more liquid and cooking time than others. Stir the cubed butter into the cooked grits and remove from heat.
Step 2While the grits are cooking, start on the ragout.
Step 1In a large saute pan, cook the bacon over medium-high heat until it is cooked but not crisp, 8 to 10 minutes. Drain any excess fat and stir in the red peppers, cooking until the peppers are softened.
Step 2Stir in the shrimp, tomatoes, Creole seasoning, and stock and cook over until the shrimp are nearly cooked, 2 to 4 minutes.
Step 3Reduce the heat to medium-low and stir in the chopped butter and one-half of the green onions. Continue cooking until the shrimp are just cooked through and are firm, opaque and pink; be careful not to overcook or the shrimp will become rubbery. Taste and add hot sauce if desired.
Step 4Remove from heat, and hold in a warm place if the grits are not yet ready.
Step 5To serve, divide the warm grits among 6 shallow bowls and top with the ragout. Sprinkle over the remaining green onions and serve immediately.