Place flour in a shallow bowl. Rub salt and pepper into both sides of fish; dredge in flour to coat both sides.
Coat a large skillet with cooking spray and set over medium-low heat; melt butter in oil.
Add fish; cook for 2 to 3 minutes on one side. Flip fish; cook about 2 to 3 minutes more depending on thickness of fish. Remove fish to a serving plate; sprinkle with herbs. Yields about 3 1/2 ounces per serving.