Add the soy sauce, tomato paste, Worcestershire sauce, garlic powder, brown sugar black pepper to the slow cooker and mix together.
Add the diced chicken breasts, red bell pepper and a can of pineapple chunks (including the juice) into the slow cooker.
Gently stir the ingredients in the slow cooker, ensuring the chicken and bell peppers are evenly coated in the marinade.
Set your slow cooker to low and cover it with the lid. Cook for 4-6 hours. You can also cook on high for 2-3 hours.
About 30 minutes before serving, taste the sauce and adjust the seasoning if necessary. You can add more soy sauce or brown sugar if desired.
Optionally, garnish with sliced scallions and serve over rice.
Notes
You can include some red pepper flakes or diced jalapeños to spice up the dish.Be careful with the soy sauce as it can be salty; taste and adjust gradually.Keep an eye on the slow cooker, especially if you're cooking on high, to prevent overcooking and drying out the chicken.