Peeling was the act of removing the outer layer of a vegetable or fruit. A vegetable peeler was commonly used to perform this action.
In 2370, while pretending to be Chef in a holographic simulation of Enterprise NX-01's final mission, William T. Riker asked a hologram of T'Pol to peel carrots for him. Later, a hologram of Trip Tucker ate one of the carrots, not minding that they weren't peeled yet. (ENT: "These Are the Voyages...")
While operating on Seven of Nine in 2374, The Doctor commented that removing her Borg implants was like peeling an onion. (VOY: "The Gift")