"Grind Meat" is an objective in the quest The Hunger Pangs in The Horrible Hunger of the Ravenous Wattle Gobbler DLC
Head over to the West from the back room in the Freezeburn Fridge. You need to make it back to the Cocina de los Diablos, so go South then East. Once inside the Kitchen again, go up the stairs on the left, above the conveyor belt. Head to the corner just past the break in the railing. You will find the switch you need there. Hit it 3 times to grind up all the skag meat. You're not done with it yet as it needs to be marinaded.