Thaw fish, if frozen. Pick tarragon leaves from the stalks. You should have about 1/4 cup of loosely packed leaves.
Put leaves and butter in food processor. Pulse until leaves have a chopped consistency- don't over process.
Heat a non-stick skillet over medium heat. When heated, drop butter by 1 heaping spoonfull into the skillet. Immediately place a filet into the bubbly butter. Cook until desired doneness, usually light golden brown. Don't forget to flip. Repeat with each filet. Salt and pepper to taste. Enjoy.