Let the butter soften at room temperature.
Finely chop the fresh rosemary and mince the garlic.
In a bowl, combine the butter, rosemary, garlic, lemon zest, black pepper, salt, and parsley.
Mix thoroughly until all ingredients are evenly incorporated.
Roll the butter into a log using parchment paper or transfer it to an airtight container.
Refrigerate for at least 1 hour until firm.
Slice or melt over grilled meats, roasted vegetables, potatoes, seafood, or fresh bread.