Hot-and-Spicy Chicken With Peaches

Ingredients

• 1/4 cup tamarind paste
• 1 vanilla bean, split in half
• 2 tablespoons rice-wine vinegar
• 2 teaspoons light-brown sugar
• 3 tablespoons low-sodium soy sauce
• 1/4 teaspoon freshly ground pepper
• 2 teaspoons canola oil
• 1 whole skinless, boneless chicken breast (12 ounces), cut into 1/2-inch-wide strips
• 1 onion, sliced into 1/4-inch-thick half-moons
• 2-inch piece ginger (3/4 ounce), cut into 1/8-inch-thick matchsticks, plus more, finely chopped, for garnish
• 1/2 green chile, finely chopped, plus more thinly sliced for garnish
• 2 ripe but firm peaches, peeled and cut into 1/2-inch-thick slices
• 10 ounces baby bok choy, cleaned and stems trimmed
• 1 scallion, sliced 1/8-inch thick for garnish