Clean the mushrooms with a slightly damp paper towel to remove debris.
Bring around 1 liter to water to a boil, add a pinch of salt and boil the mushrooms for 10 minutes.
Transfer the mushrooms on a plate with kitchen paper and allow to cool down.
Pat dry the excess of water and cut the mushrooms into a cutlet shape. To do so place them on a chopping board and, using a sharp knife, make a slit from the cap to the stem, then start slicing around 5mm thick of the flash in a spiral motion.
Gently score both sides into a diamond pattern to avoid the mushrooms to curl back up.
Prepare 3 bowls or dishes: one with flour, one with unsweetened plant milk and a third one with panko breadcrumbs + salt and pepper. Note: You can add extra herbs and spices to taste to this mixture if you prefer to pack ever more flavours.
Evenly coat each mushroom first in the flour, then in the vegan milk and finally in the breadcrumb mixture.
Spray the air fryer basket with some vegetable oil, then arrange the mushroom cutlets avoiding them to overlap. See notes for other cooking methods.
Cook first for 7 minutes at 180° C (350° F). Then flip the cutlets, lightly spray with some extra vegetable oil and cook for another 5 minutes at the same temperature.
Serve immediately with some sea salt flakes sprinkled on top.