The Preparation
Let butter soften slightly so it folds easily.
Add herbs and lemon zest. Fold together gently.
Taste and season with flaky salt.
Lay on parchment paper. Shape into a log. Roll parchment around it and twist the ends.
Refrigerate until firm, or use immediately. **Note:** Rosemary is assertive. Start with less than you think and taste as you go.
The Chef's Notes
Rosemary is strong — use less of it than the other herbs. The lemon zest is what lifts the whole butter and keeps it from feeling heavy.