Chicken and Broccoli Stir-fry

INGREDIENTS

• 3 tablespoons vegetable oil
• 3 scallions, whites only, thinly sliced on an angle
• 1 tablespoon dry sherry
• 1 tablespoon soy sauce
• 1 pound chicken breast (about 2 breasts), cubed
• 1 1/4 teaspoons salt
• About 1/3 cup water
• 1 tablespoon hoisin sauce
• 3/4 to 1 teaspoon red chili flakes, optional
• Garnish: toasted sesame seeds, optional
• 2 tablespoons sugar
• 1-inch piece peeled fresh ginger, minced
• 2 cloves garlic, minced
• 1 tablespoon, plus 1 teaspoon cornstarch
• Serving suggestion: Jasmine rice
• 1 tablespoon dark sesame oil
• 5 to 6 cups broccoli, trimmed sliced stalks and medium florets (keep the 2 cuts separate)