1. Combine ingredients except kale in small saucepan. Heat until slightly warm and combined. Transfer mixture to bowl and stir in kale leaves. Cover with plastic wrap and refrigerate, allowing kale to soak for at least 4 hours.
2. Preheat grill or cast-iron grill pan over high heat. Remove kale from refrigerator and stir to make sure leaves are well covered in marinade. Using metal tongs, place kale on grill in single layer. Cook for 45 to 60 seconds, or until leaves are sizzling, turn over and grill other side for another 45 to 60 seconds, or until leaves have visibly softened. Serve immediately.