1.  To prepare wheat berries, fill a pot three-quarters full with water and bring to a boil over high heat. Add generous pinch of salt and add wheat berries. Lower heat and simmer 35-60 minutes; different wheat berries will vary. Drain and return to pot. Off heat, toss still-warm grains with vinegar, another pinch salt, and olive oil. Let cool.

2.  To prepare salad, whisk vinegar, 2 pinches salt, and olive oil in large mixing bowl. Gently toss melon, vegetables, and cooled wheat berries in vinaigrette with greens and half the herbs. Turn out salad on wide serving platter and top with feta and remaining herbs. 

The salad - without melon, herbs, and cheese - can be cooked and dressed up to 2 days in advance; let come to room temperature before adding the reserved ingredients and serving.