Using kitchen shears, cut the backbone out of the chicken. I immediately put this in a plastic container and store in the freezer to make stock when I have time. Place chicken breast side up in a roasting pan. Press down on chicken to help it lay flat.
Combine the herbs, garlc, salt, pepper, zest and juice in a mortar and pestle. Once all ground up add the butter and combine well.
Spread 2/3 of mixture under the chicken skin and and dot/spread remaining butter all over chicken.
Bake uncovered at 425˚F for 45 min or until instant read thermometer reads 160˚F when inserted into thickest part of chicken breast. Remove form oven and rest uncovered 10 minutes on a cutting board before serving.
