How do I make a super oily surface? Like the patty in this burger :

As you can see, its looks very wet from the oil, its covered with liquid. How to achieve this?
And here is my patty and its nodes settings, it looks dry:
Comment echo: add better lighting. A flat grey background is a recipe for boredom. Try the HDR textures in blender’s own data files as environment textures.
As for the oil, try the clearcoat setting in the Principled shader. It was made for just such a purpose.
Also, nice burger