In a large mixing bowl toss the cut, blanched green beans, plum tomato strips, red onion, and toasted sesame seeds. In the bowl of a food processor fitted with a chopping blade combine the white vinegar, sesame oil, vegetable oil, chopped garlic, sugar, soy sauce, and peanut butter then pulse until fully incorporated. Pour the dressing over the green bean mixture and mix well. Taste and adjust the seasoning with salt if necessary. Place in a large serving bowl. Makes 6-8 servings.