Pointcast? - Raycast Point X from same Point X

I'm trying to find the normal of a Mesh at a known position, where that known position is not a vertex.

Normally it would be very easy to just Linecast/Raycast to get the normal at this position, but the ray will often hit the wrong position, returning the wrong value.

Is there some way to start and end a Raycast at this specific position?

Or is there some other way to get the normal at an arbitrary position on the mesh?