Select a large sauté pan with a tight-fitting lid. Smear with butter and scatter chopped shallots on top. Lay sole fillets on a work surface. Spread chopped tarragon over each fillet. Season with remaining salt and pepper. Beginning with wide end, roll up fillets and place in pan, with ends tucked underneath. Sprinkle white wine around fillets, cover, and place over medium-high heat. As soon as juices begin to run and bubble, reduce heat to low and cook, covered, for 3 minutes. Remove from heat. Keep covered.