Add garlic, chicken stock, lemon juice, and dill to a small saucepan over medium heat. Bring to a boil and boil for about 2 minutes. Reduce heat and whisk in mustard and heavy cream. Continue to cook until it thickens, making sure to whisk the entire time. Remove from heat and Whisk in butter pieces one at a time. Add cayenne pepper, salt and pepper.
Makes 1/2 cup. Nutrition information is for 1 tablespoon serving.