Place ground beef into the instant pot. Turn saute mode on and click it a second time to make it on high heat saute mode. Add in garlic and ginger. Cook until meat is browned.
Add in pineapple and red peppers. Place lid on the pot for 2 to 3 minutes. Open to stir. This will make the peppers tender. No need to pressure cook.
Mix together coco aminos or teriyaki sauce with the cornstarch and brown sugar. Whisk well. Add to the beef mixture and on saute mode keep stirring the beef until the cornstarch thickens the juices.
Add in pepper and stir well. Serve over rice. Top with sesame seeds.