Peel and segment pummelo.
Peel and segment Melogold. Reserve 3 tablespoons juice; save the remainder for other uses.
Rinse mint, tarragon, chervil, and basil; gently pat dry. Stack basil leaves and cut crosswise into thin strips. Mix herb leaves, cut basil, and chives. Mound herb mixture equally on plates.
In a small bowl, mix reserved 3 tablespoons Melogold juice and oil. Drizzle half the dressing evenly over herbs.
Arrange pummelo and Melogold segments on herbs. Drizzle segments equally with remaining dressing. Add salt and pepper to taste.