Made 30 slices.
This achievement is easy and straightforward, but will take some time as you need to obtain the meat to work with.
Meat (or Flesh, as it’s called when you harvest it from bodies in the morgue) can be removed from bodies at the cost of ‘damaging’ the corpse. Collecting these and taking them to your Home allows you to slice the meat at the cooking table (which you can then cook in the oven).
All this achievement requires is for you to create 30 slices, which means you’ll need to harvest at least 30 Flesh from bodies, and then turn them into meat slices at your cooking table.