Cowboy butter is essentially an easier-to-make version of a compound butter that marries together any and every ingredient that pairs well with steak. Each recipe varies a bit, but the main stars tend to be butter, lemon, garlic, dijon mustard, paprika, cayenne, red pepper flakes, and fresh herbs like parsley, thyme, or chives — with some recipes including Worcestershire sauce, horseradish, or shallots.