In large skillet, on medium-high, heat sesame oil and sauté chili, garlic, and ginger for about 2 minutes, stirring constantly to keep garlic from burning. Add crushed peppercorns and lower heat slightly. Drain bok choy pieces and, without drying them, add to pan and sauté for a further 2 minutes, stirring constantly. The garlic should start to get crispy, but if it doesn’t, turn heat up slightly. Add vinegar and remove from heat.
