Ingredients

• 1 (1 1/4 pound) pork tenderloin, trimmed of silver skin

• salt and ground black pepper

• ⅓ cup ketchup

• ⅓ cup seasoned rice vinegar

• 1 (8 ounce) can pineapple chunks, drained with juice reserved

• 2 tablespoons brown sugar

• 4 cloves garlic, minced

• 2 teaspoons hot chili sauce (such as Sriracha®)

• 1 teaspoon soy sauce

• 1 pinch red pepper flakes

• 1 tablespoon vegetable oil

• 1 teaspoon butter

• ¼ cup chopped green onion (white part only)

• 2 tablespoons chopped green onion tops