Mix together the balsamic vinegar, dijon mustard, honey, sea salt, and pepper in a small bowl. Once combined, drizzle in the olive oil while constantly whisking. If mixture is not think enough add an additional tablespoon of olive oil. Set aside.
Put chopped pistachios in a shallow dish. Divide goat cheese into 12 equal balls. Roll each ball in the pistachios until well coated. Set aside.
Divide greens into four salad bowls and place three cheese balls and 1/4 cup grapes on each.