Author Notes: There are countless ways to prepare a simple roast chicken, but sometimes you want and need a go-to preparation that you can turn to again and again without overthinking every single detail. This buttermilk roast chicken with potatoes and cornichon butter is that preparation for me. It takes a cue from fried chicken by relying on a simple brine of buttermilk and pickle juice, resulting in a beautifully bronzed, crackly-skinned, evenly seasoned and tender bird every single time. 

Buttermilk Roast Chicken with Potatoes and Cornichon Butter

Serves 4

• 1whole chicken, about 4 pounds
• 1cup buttermilk
• 1cup pickle juice, from any type of pickles (dill, bread and butter, spicy garlic, etc.)
• Kosher salt, to taste
• 1 1/2 to 2pounds baby potatoes, halved, or small golden potatoes, peeled and sliced 1/4-inch thick
• Olive oil
• 1tablespoon butter, softened
• 4cornichons, finely chopped
• 1tablespoon finely chopped flat-leaf parsley

1. Mix together buttermilk, pickle juice, and 1 teaspoon kosher salt. Place chicken in a gallon-sized plastic zipper-lock bag. Pour in the brine. Seal the bag, pressing out as much air as possible. Refrigerate 6 to 24 hours (a longer brine will result in a more flavorful bird).
2. About an hour before you roast the chicken, remove chicken from the bag and discard brine. Pat chicken dry with paper towels. Rub a little olive oil on the bottom of a large baking dish or ovenproof skillet (one large enough to hold the potatoes). Place the chicken in the middle of the dish, breast-side up, and let it come to room temperature.
3. Heat oven to 425° F.
4. Toss potatoes with 1 tablespoon olive oil and kosher salt, to taste. Arrange potatoes around the chicken. Evenly rub the chicken with 1/2 to 1 tablespoon olive oil. Season the chicken and potatoes with freshly cracked black pepper.
5. Place the chicken and potatoes in the oven and roast for about 50 to 70 minutes, rotating once, until the juices run clear or the thickest part of the thigh registers 165° F. (If the chicken is browning too quickly relative to its internal temperature, reduce the oven to 375° F to 400° F.)
6. Meanwhile, mash together the butter and cornichons with a fork. Don’t worry if they’re not completely integrated.
7. When the chicken is done, immediately remove it from the pan and rest on a cutting board for 10 to 15 minutes before carving. Add the cornichon butter and parsley to the hot potatoes. Once it starts to melt, toss to evenly integrate.

https://food52.com/recipes/75666-buttermilk-roast-chicken-with-potatoes-and-cornichon-butter