Combine flour, cornmeal, paprika, 1/2 teaspoon salt, and pepper in a large, shallow plate. Dredge fish, one at a time, in mixture.
Heat oil in a large, nonstick sauté pan over high heat just until smoking. Carefully add fish fillets in a single layer. (Do not overlap fillets or overcrowd the pan.) Cook over high heat 1 1/2 to 2 minutes or until golden brown and slightly crispy on one side.
Turn fish fillets over with a spatula. Add tarragon and butter to pan. Cook about 1 minute or until fillets just begin to flake and butter turns golden brown. Transfer fillets to serving plate. Season to taste with salt. Serve warm with lemon wedges.