Add the meatballs and peppers and onions to the slow cooker.
Drain the juice from your can of pineapple into a medium bowl
Add the pineapple to the slow cooker.
Add the vinegar, soy sauce, ketchup, brown sugar, garlic, and cornstarch to the pineapple juice and whisk until combined.
Pour sauce over the meatballs and stir to coat.
Cook on low for 3-4 hours, or on high for 2-3 hours.
Sprinkle with sesame seeds and chopped scallions.
Serve!
Video
Notes
You can use mini or regular-sized meatballs.If your sauce is too thick just add 1/4 cup of water to thin it out a bit.You can use about 2 cups fresh peppers and onions if preferred.