In a medium skillet set over medium heat, heat the olive oil. Add the onion, and celery and cook, stirring, until tender but not browned, about 3 minutes. Add the tomatoes, bell pepper, garlic, Worcestershire sauce, chili powder, salt and pepper and cook, stirring, for 5 more minutes. Add the shrimp. Cover and cook until the shrimp are opaque and cooked through, 5 minutes.

In a large saucepan set over medium-high heat, bring the liquid (chicken stock or water) and the salt to a boil. While whisking constantly, slowly pour the grits into the boiling water. Reduce the heat to low and simmer, whisking often, until the grits become thick and creamy, about 5 minutes. Remove from the pan from the heat, stir in the cheese.

Divide the grits among serving dishes. Spoon the shrimp over the grits and drizzle with the pan sauce.