Cook 3/4 pound chopped wax beans and 2 bunches quartered radishes in boiling water, 5 minutes. Remove with a strainer and run under cold water. Add 1 1/2 pounds halved baby potatoes to the boiling water and cook 6 to 8 minutes; drain. Toss the potatoes, beans and radishes with 1/4 cup lime juice and 2 tablespoons sugar. Stir in 3/4 cup each mayonnaise and chopped scallions, 4 teaspoons grated ginger, 1 teaspoon salt and some chopped cilantro and parsley. Chill.