Thaw shrimp, if frozen. Preheat oven to 400 degrees F. Peel and devein shrimp, leaving tails intact if desired. Rinse shrimp; pat dry with paper towels. In a large bowl combine shrimp and 1/2 teaspoon of the Cajun seasoning; toss gently to coat. Set aside.
In a 10-inch cast-iron skillet or large oven-going skillet, cook sweet peppers, celery, and onion in hot oil over medium-high heat for 5 to 7 minutes or until vegetables are tender, stirring frequently. Add shrimp and garlic. Cook and stir for 2 to 3 minutes or until shrimp are opaque.
Stir in black-eyed peas, tomatoes, and the remaining 1/2 teaspoon Cajun seasoning. Spread mixture in an even layer. Drop Corn Bread Dumplings into eight mounds on top of shrimp mixture.
Bake, uncovered, for 15 to 18 minutes or until a toothpick inserted in centers of dumplings comes out clean. Let stand for 5 minutes before serving. If desired, sprinkle with parsley.
Corn Bread Dumplings
In a medium bowl stir together flour, cornmeal, sugar, baking powder, and salt. In a small bowl combine egg, milk, and oil. Add egg mixture all at once to flour mixture; stir just until moistened.