Is this a truffle
I found this firm ground thing in my yard it has the firmness of an jicama and has a musty smell. it is about 2 to 3 inches below the ground surface in the shade under a birch tree. A chef who lives across the street looked at it and wasn’t sure if it was a truffle or not. He said it had the markings and inside the big one has the veins that he has seen before but he’d never seen one with the white outside and black inside. Any recommendations?