My first thought was to combine it with some fries. After peeling a potato, I made a stock out of the left over onion from the puree and the potato skins and parboiled the fries in it.
With a bit of modification, I made the
Homemade Heinz-Style Ketchup and added it to the dripping found in the pan I roasted the onion in (very tasty stuff).

I took the picture and my son ate the fries in about 20 seconds. He said, "[sic] it tasted good with the onion stuff. Make some more."