PPlace potatoes in a large pot and over with water. Add 1 Tablespoon salt, bring to aboil and cook until potatoes are tender, about 10 minutes. Drain and cool. When potatoes are cool enough to handle, cut each one into quarters.
Place potatoes in large bowl. Sprinkle potatoes with vinegar and let stand q10 minutes. Add celery, green onions, peppers and parsley. Drizzle with olive oil and season with salt and pepper. Serve at room temperatire.