Cut the tofu block into 0.5cm slices (with a 200-gram block I’m making 4 slices).
Place the slices in the freezer overnight. This step is optional but will give a chewy texture. Take them out and leave to defrost on a kitchen towel.
Press the slices to get rid of water.
In a bowl, whisk together the water, nutritional yeast, fleur de sel and fire cider (or apple vinegar).
Marinate the slices for 30 minutes in the freezer, then fry in the olive oil in a pan for about 6-8mn, flipping slices halfway.