Combine buttermilk, garlic powder, parsley, salt and pepper in a small, shallow dish or a zip-top bag. Stir to combine. Place chicken breasts in the marinade, toss to coat, and refrigerate for two hours (or overnight).
For the Asiago Buttermilk Dressing:
Combine all dressing ingredients in a medium bowl. Whisk to thoroughly combine. Taste, and season with salt additional salt if needed. Cover and refrigerate while you grill the chicken, or while the chicken marinates.
For the Kale Salad:
Remove chicken from the buttermilk, and shake off as much as possible. Heat an outdoor grill or grill pan over medium heat, and grill chicken for about 4-5 minutes per side, until cooked through (reaches 165 F internally). Set the chicken aside to rest while you prepare the salad.
If using whole kale, tear the leaves off into small pieces, discarding most of the thick stems. Massage kale with one heaping teaspoon of extra virgin olive oil and a pinch of salt until all of the kale is coated, and noticeably softer. Divide kale between two bowls.
Slice the chicken, and divide it between the salads. Drizzle salads with buttermilk asiago dressing, then top with toasted croissant croutons and additional Asiago cheese (if desired.) Freshly cracked pepper on top is always nice, too!