Add lemon to a saucepan over medium heat and add garlic, cooking until lemon juice reduces. Add in pepper flakes, paprika, cayenne pepper, pepper, Dijon, horseradish. Add more red pepper flakes if you want it spicier.
Reduce heat to low. You don’t want the sauce to reach a boil. Add butter in one tbsp at a time, whisking continuously. Stir in thyme, parsley, chives and salt.
Serve over steak, seafood, veggies, etc.
