Heat the oil in a large saucepan over medium heat.

Sauté sliced onion in the oil for 5 minutes, until onions are soft but not brown.

Add water, corn syrup, tomato paste, cornstarch, salt, and red pepper flakes, and stir.

Bring mixture to a boil.

Reduce heat and simmer for 20 minutes.

Add vinegar.

Continue to simmer for an additional 10 minutes or until most of the liquid has reduced and the sauce is thick.

Spoon over hot dogs, burgers, brats, etc.

*This recipe makes about 1 1/2 cups.*