Preparation Combine zests and salt on a cutting board. Chop, dragging the knife blade at an angle across mixture, until a coarse paste forms. Transfer to a small bowl. Mix in remaining ingredients. Transfer to a small jar, cover, and chill for 2 days. DO AHEAD: Can be made 2 weeks ahead. Keep chilled.
Preparation Combine zests and salt on a cutting board. Chop, dragging the knife blade at an angle across mixture, until a coarse paste forms. Transfer to a small bowl. Mix in remaining ingredients. Transfer to a small jar, cover, and chill for 2 days. DO AHEAD: Can be made 2 weeks ahead. Keep chilled.