Cut turkey meat into evenly-sized pieces suitable for your meat grinder; place in freezer and chill until hardened but not frozen through.

Preheat oil in a medium frying pan and sauté onion for 2-3 minutes. Add parsley and tarragon and sauté 30 seconds longer; remove from heat. Place chilled turkey meat in a large bowl, add sauteéd mixture and remaining ingredients except oil for frying. Stir to combine, and process through meat grinder.

Form the ground turkey mixture into burgers, 5-6 inches wide and 1 1/2 inches thick. Handle meat as little as possible. Preheat oil in a heavy frying pan over medium-high heat. Test the oil by dropping a little bit of turkey mixture into the oil. If it begins to sizzle immediately, the oil is ready. Cook 3-4 burgers at one time, four minutes per side or until cooked through. They will puff up a little. Do not cover and do not pat down. They should be firm to the touch when pressed in the middle. If not firm, cover, reduce heat to medium and cook another few minutes.