4 to 5 pound whole chicken (or equivalent chicken pieces)
1/2 c. Greek yogurt
1/4 c. milk
2 Tbsp. Garlic Olive Oil
1 oz. fresh tarragon sprigs, divided
1 Tbsp. sweet Hungarian paprika
1 tsp. Kosher salt
1/2 tsp. onion powder
freshly ground black pepper
Rinse chicken. Using poultry shears, cut chicken in half, lengthwise through the breast. Cut along backbone on either side, ending with two halves. (Discard backbone or freeze for chicken stock.) Rinse chicken halves and pat dry. Place chicken halves, cut sides together, in a large heavy freezer zip-top bag. Whisk together Greek yoghurt, milk, and Garlic Olive Oil. Pour over chicken in the bag. Push 3/4 of the tarragon sprigs in between the chicken halves and around the outside. (Reserve remaining tarragon sprigs for garnish.) Seal the bag after pressing out all of the air. Massage chicken so the pieces are all coated with the wet mixture. Refrigerate at least 8 hours or overnight. When ready to roast, preheat oven to 375F. Line a deep roasting pan with foil. Place a rack in the pan. Fish out the tarragon sprigs from the yogurt/milk marinade and arrange on the rack. Discard marinade. Place the chicken halves, skin-side up, on top of the tarragon sprigs.
Combine paprika, salt, onion powder, and garlic powder. Sprinkle evenly over the chicken halves, then top with freshly ground black pepper. Roast chicken for 1 hour, until golden. Brush with Garlic Olive Oil once or twice while baking to get crispy. The thickest part of the chicken half should reach 165F. on a meat thermometer, and the juices should run clear when pierced. Let the chicken rest 15 minutes, then cut each half in half again for 4 servings. Garnish with reserved fresh tarragon.