Ensure the butter is fully softened at room temperature—it should press easily without melting. Finely chop the nasturtium petals, chives, and parsley so they blend evenly.

Combine the butter with the chopped petals, herbs, lemon zest, salt, and pepper. Mix until evenly distributed and lightly speckled. If the butter feels too firm, let it sit a few more minutes.

Spoon the mixture onto parchment paper or plastic wrap and roll into a log, pressing gently to remove air pockets. You can also press it into molds if preferred.

Refrigerate for at least 1 hour until firm enough to slice cleanly.

Slice into rounds or scoop as needed. Let it soften slightly before serving for the best texture and flavor.