In a large saucepan, bring the chicken broth to a rolling boil over high heat. Season the broth generously with salt. Add the chicken pieces and reduce the heat to low once it reaches a simmer. Cover and cook gently for about 40 minutes, or until the chicken is tender and cooked through. Once done, carefully remove the pieces, pat them dry with paper towels, and place them on a platter. Cover loosely with foil to keep them warm.

While the chicken is simmering, prepare the frying setup. Pour the grapeseed oil into a deep, heavy-bottomed pot with high sides. Heat the oil over high heat until it reaches 400°F. Place a wire rack over a rimmed baking sheet or line a large plate with several layers of paper towels for draining the chicken once it’s fried.

In a shallow dish or large bowl, mix the flour with paprika, celery salt, black pepper, 1 teaspoon of salt, and cayenne pepper (if using). Whisk the dry ingredients together until fully combined and evenly distributed.

Place the warm, pre-cooked chicken in a large bowl and pour over the buttermilk. Gently toss the pieces to ensure they are evenly coated. Take each piece and dredge it in the seasoned flour mixture, then return it to the buttermilk briefly, and dredge once more in the flour. This double coating creates an ultra-crispy crust. Shake off any excess flour before frying.

Working in small batches of two pieces at a time, carefully lower the chicken into the hot oil. Fry for 30 seconds to 1 minute, or until the crust turns deep golden brown and crispy. Use a slotted spoon or tongs to transfer the fried chicken to the prepared rack or paper towels to drain.

Serve hot, with your choice of sides like coleslaw, mashed potatoes, or cornbread.