Chicken:
1. Salt chicken all over and place in a large ziplock bag. Pour buttermilk over the chicken and allow to marinate overnight.
2. Set oven to 400°F degrees. Remove excess buttermilk from chicken and salt the inside of the chicken. Set the chicken with the skin side up over Big Chill on Holy Sheet.
3. Slice butter into ½ inch slivers and tuck between the chicken skin and meat on the breast, thighs, and legs. Tear tarragon and stuff underneath the skin with the butter.
4. Mix mayo and dijon in a small bowl and using a pastry brush or spatula paint a light layer of the mixture over the chicken. Season with fennel seeds and garlic powder, and more salt and pepper. Roast for 45 minutes and let rest for another 10 minutes.
Aioli:
Combine egg yolk, dijon and salt. Slowly stream oil in while whisking the egg yolk mixture. Start slowly first and then gradually stream in more oil. As the aioli thickens add the preserved lemon juice to “loosen” it up. Stir in preserved lemon at the end.
Salsa verde:
Combine all ingredients in a small bowl adding more salt and pepper to taste.