Put the frozen meatballs in a large saute pan in a single layer (hence the 12" or larger pan) over med-high heat for about 10 minutes.
Add all the ingredients except water and cornstarch.
Gently stir to combine, cover and reduce heat to medium-low heat.
Simmer for 20 minutes.
Combine water and cornstarch in a measuring cup (or use one of the large empty tomato cans) and stream into the sauce while gently stirring until it starts to thicken.
Cover and simmer on low for another 10 minutes.
Notes
* I simmer for about an hour - out of habit.=====You can also make this in a slow cooker on low for 8 hours or high for 3 hours.