In a pie plate, whisk the cornmeal, panko, 1/2 cup of flour, the salt, cayenne, garlic powder, onion powder, thyme, sage, ginger and cumin. In another pie plate, beat the eggs. Dust the catfish with flour, then dip in the beaten egg; coat in the panko mixture, pressing the crumbs to help them adhere. Transfer the fish to a baking sheet.
In a skillet, heat 1/4 inch of vegetable oil. Fry the catfish in 2 batches over moderately high heat, turning once, until the crust is golden and crisp and the fish is cooked through, 4 minutes. Drain the fish on paper towels.
Spread the rolls with the remoulade. Top with the fried fish and romaine and serve.