Stand corn upright in a medium bowl and slice off corn kernels with a sharp knife. Using back of knife, scrape along the cob to release corn milk into bowl. Add peach (making sure to get all of the juices into the bowl too), red onion, chiles, garlic, ginger, cilantro, and peanuts to bowl and toss to combine. Sprinkle with pepper, 1 tsp. sugar, and 1 tsp. chaat masala and toss again. Divide between shallow bowls.