How to Make It
Bring chicken broth and 3 cups water to a boil in a medium saucepan over high. Whisk in grits; reduce heat to medium. Cover and cook, stirring occasionally, until tender, 20 to 23 minutes.
Meanwhile, heat oil in a large nonstick skillet over medium-high. Add onion and poblano; cook, stirring often, until onion is softened, 8 to 9 minutes. Add garlic; cook 1 minute. Stir in diced tomatoes, Worcestershire, black pepper, and 1/4 teaspoon salt. Simmer 5 minutes. Add 1 tablespoon butter; cook, stirring often, until butter is melted. Add shrimp, and cook until just pink, 3 to 4 minutes.
Add 6 tablespoons Parmesan, half-and-half, remaining 3 tablespoons butter, and remaining 3/4 teaspoon salt to grits; stir to combine. Divide grits among 6 bowls; top with shrimp mixture. Sprinkle with scallions and remaining 2 tablespoons Parmesan; drizzle evenly with hot sauce.