Rinse and pat the fish dry. Put the buttermilk, dill, garlic salt, and pepper in a large, shallow dish and mix well. Soak the fish in the buttermilk mixture for 10 minutes, turning frequently. Reserve 1 cup of the buttermilk marinade for the sauce. Put the Cream of Wheat in a separate, shallow dish. Warm the oven to 200°F. Heat a large, nonstick skillet over medium-high heat. Add two tablespoons of the oil. Dredge each fillet in the Cream of Wheat. Cook two fillets in the skillet, 2 to 3 minutes on each side, or until light golden and crisp. Drain on paper towels, then transfer to an ovenproof plate and keep in the oven until ready to serve. Repeat with the remaining fillets.
 

Put the reserved marinade and butter in a small saucepan. Bring to a gentle boil over medium-high heat, whisking until the butter melts. Whisk in the lemon juice. Arrange each fillet in a shallow bowl and surround with ¼ cup of the sauce. Garnish with dill, if desired.