Season steak bites with salt and pepper.
Heat olive oil in a skillet and quickly sear the steak pieces until lightly browned.
Transfer steak to the slow cooker.
Add pineapple chunks.
In a bowl whisk pineapple juice, teriyaki sauce, soy sauce, brown sugar, garlic, and cornstarch.
Pour sauce over the steak.
Cook on low for 4–5 hours until steak is tender.
Stir the sauce before serving.
