Yum Yum...! I hit the jackpot last week when making some pasta sauce but now need some more info.

I chopped up some tomatoes, added a few herbs n spices, 300ml water & then let it simmer on the stove...I then added some tomato paste & chicken...ooo..mmmm....

So, my question is: How do i thicken the sauce without the tomato paste? Cornstarch???

Ta!
C