Add all ingredients to the slow cooker (except peanut butter, peanuts, water and cornstarch)
Cook on high for 4 hours (or medium for 6, low for 8)
Add peanut butter to the slow cooker and mix in.
In a small bowl, whisk the cornstarch in the cold water.
Add to a small sauce pan and heat over medium.
Add about 1/4 cup of liquid from the slow cooker to the sauce pan and whisk until it becomes bubbly, thick and smooth.
Place thickened liquid into the slow cooker and mix in well.
Cook for another 10 minutes.
Serve over rice and top with chopped peanuts and green onions.