In a medium pot add the pineapple juice, water, vinegar, sugars, salt, soy sauce and ketchup.
Bring to a low boil.
In a small bowl, whisk the cornstarch with the water.
Pour this into the boiling mixture and simmer for about 3-5 minutes.
Sauce will be bubble and thicken when it's ready.
No need for take-out with this quick and easy sweet and sour sauce on hand. Pour it or use it for dipping, either way it's delicious!