Combine all ingredients except pineapple, snow peas, cornstarch, water, salt, pepper and rice in slow cooker. Cover and cook on low 6-8 hours, adding pineapple and snow peas during the last 15 minutes.
Turn heat to high and cook 10 minutes; stir in combined cornstarch and water, stirring until thickened, 2-3 minutes. Season to taste with salt and pepper. Serve over rice.