Butter should be at room temperature. Cream butter in small bowl using a fork or electric mixer.
Gradually blend in miso paste, chives, garlic, red pepper, and salt.
Butter mixture can be used while still soft; or it can be rolled into a cylinder in parchment paper or plastic wrap and refrigerated or frozen, then sliced into teaspoon-sized rounds.
Flavored butter can be stored a couple days in the refrigerator or it can be frozen for several weeks.
Allow 2 or 3 teaspoons per serving. Place by teaspoonful or sliced round on the top of hot broiled or grilled fish.