Sweet-and-Sour Pork Stir-Fry

INGREDIENTS

• 1 can (8 ounces) pineapple chunks in juice, drained (juice reserved)
• 2 tablespoons rice vinegar
• 2 tablespoons soy sauce
• 1 tablespoon cornstarch
• Coarse salt and ground pepper
• 2 tablespoons vegetable oil
• 1 pork tenderloin (about 1 pound), halved lengthwise and thinly sliced
• 6 scallions, white and green parts separated, cut into 1-inch lengths
• 2 bell peppers (ribs and seeds removed), cut into 2-inch pieces
• 1 package (10 ounces) frozen broccoli florets, thawed and patted dry
• Cooked rice, for serving