How is this mashed onion paste called?

I usually make vinaigrette by adding typical ingredients (garlic, a mix of olive and oil, etc.) and mixing all that together with a blender.

I once added (I am not sure why anymore) some onions to the mix and after blending I got some kind of thick paste. I do not remember the taste anymore but it was probably not extraordinary.

I am curious if such a paste of blended onion and oil (and garlic, spices, …) is actually used for something useful in cooking?