Combine all dressing ingredients (except salt and pepper) in a bowl. Mix well.

Preheat grill to medium-high heat (you can also broil in oven at 400 degrees Fahrenheit). Brush peaches with two tablespoons of dressing.

Grill for five to seven minutes or until peaches are softened, turning halfway through cooking, after about four minutes. Remove from grill, cool to room temperature and cut into wedges.

Slice the colored tomatoes thinly and arrange in a casual pile in the center of the individual plates or platter.

Sprinkle with scallions and place peach wedges in the center. Sprinkle salt and pepper evenly over salad.

Drizzle with remaining dressing, letting some of the vinaigrette surround the salad on the plate, and garnish with rosemary.