Preheat the oven to 400 degrees F. Butter a large baking dish and set aside.
In a large skillet or saute pan, heat the oil over medium high heat. Add the onions, celery and bell peppers and cook, stirring, until soft, about 3 minutes. Add the green onions, garlic, salt, pepper, thyme, and cayenne, and cook, stirring, for 1 minute. Remove from the heat and stir in the parsley. Let cool slightly.
Crumble the cornbread into a large bowl. Add the cooled vegetable mixture and 1/2 cup of the stock or water. Mix with your hands until the bread is moist. Fold in the crabmeat and add more stock or water 1 tablespoon at a time as needed to be moist but not overly wet (will depend upon the freshness of the cornbread). Divide into 4 portions. (Will make about 3 cups.)
Cut the catfish fillets in half crosswise and lay the 4 thicker portions in the buttered pan. Separate the smaller portions lengthwise into 2 strips each.
Place a scoop of the crabmeat stuffing in the center of each of the 4 catfish fillets in the pan, and season lightly with Essence. Arrange 2 catfish strips along the outer edges of the stuffing to surround, pressing down. Lightly season the top catfish strips with Essence and dot with butter. Bake until the fish is just cooked through and tender, 18 to 20 minutes.
While the fish is cooking, make the sauce. In a large skillet, melt the butter over medium heat. Add the onions and garlic and sautÈ until the onions are soft.† Stir in the flour and cook, stirring, to make a light roux, about 2 minutes. Add the milk, cream, and hot sauce, bring to a boil, stirring. Reduce the heat slightly and cook, stirring constantly, until thick and creamy, 3 to 5 minutes. Remove from the heat.
To serve, place a portion of the stuffed catfish on each of 4 large plates and top with the sauce. Garnish with chopped parsley and serve immediately.
Yield: 4 servings