In a large bowl or a zip-top bag, combine the buttermilk, kosher salt, black pepper, yellow curry powder, turmeric, and cumin. Mix thoroughly until the marinade is smooth and evenly blended.

Add the chicken breasts or chicken thighs to the marinade. Turn the chicken to ensure all pieces are fully coated.

Cover the bowl or seal the bag and marinate the chicken for several hours or up to overnight. If preparing the chicken for the same day, refrigerate it while marinating unless the marinating time is very brief and the environment is cool. For overnight marinating, keep the chicken refrigerated.

If desired, prepare this recipe as a freezer meal by placing the chicken and marinade together in a freezer-safe bag or container and freezing until needed.

To cook on the grill, preheat the grill to medium-high heat. Remove the chicken from the marinade and grill for about 6 minutes per side, or until the chicken is fully cooked and reaches a safe internal temperature.

To cook in the oven, preheat the oven to 425°F. Remove the chicken from the marinade and place it in a baking dish or on a baking sheet. Bake for 12 to 20 minutes, depending on the thickness and type of chicken, until the chicken is fully cooked and reaches a safe internal temperature.

Allow the chicken to rest briefly before slicing or serving.