Sprinkle fish with 1/4 teaspoon salt and pepper. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add 2 fish fillets to pan; cook 2 minutes on each side or until fish flakes easily when tested with a fork or until desired degree of doneness. Remove from pan; cover and keep warm. Repeat with remaining fish.
Add wine, broth, shallots, and garlic to pan; bring to a boil. Reduce heat, and simmer until reduced to about 1/2 cup (about 10 minutes). Remove from heat; stir in butter, remaining 1/4 teaspoon salt, chives, and tarragon. Spoon sauce over fish; serve immediately.
Wine note: The delicate, mild flavor of sole calls for a white wine that's not overtly oaky. I find that one of the new, so-called unoaked chardonnays works beautifully, especially since chardonnay often has a touch of buttery flavor that picks up on the essence of this rich-tasting sauce. New Zealand makes many of the best unoaked chardonnays. One fantastic example is Kim Crawford Unoaked Chardonnay 2005 from Marlborough, New Zealand ($17). -Karen MacNeil