Season the whole chicken generously with kosher salt on all sides and let rest at room temperature for 30 minutes.

In a bowl, combine 1 tablespoon of salt with buttermilk, place chicken in a resealable bag, pour brine over it, seal tightly, and refrigerate for 4 to 24 hours.

Remove the chicken from the fridge, discard brine, tie legs with kitchen twine, and preheat oven to 425°F.

Arrange halved baby potatoes in an oven-safe skillet, drizzle with olive oil, sprinkle with salt and black pepper, and toss until well-coated.

Position brined chicken on top of seasoned potatoes and roast in the oven for 30 minutes, then reduce temperature to 400°F and continue roasting for another 30 minutes.

Remove from oven and let chicken rest for 10-15 minutes before garnishing with fresh chopped parsley and serving.