For the fishless fish filets:
For better results, on this step, all the ingredients and the food processor cup and blades should be very cold!
Shred the oyster mushrooms with your hands, add them to the food processor and pulse it 4 or 5 times, scrape the cup sides, add the remainder of the ingredients, pulse it 3 or 4 times more.
Add the rice flour or all-purpose flour to a plate, make the paddies, very gently, then flour both sides of the filets, place them gently on a plate lined with cling film, cover them with a aluminum foil or cling film, put them in the freezer for at least 30 minutes, for better results, 2 hours.
If you would like to freeze your fishes fillets for frying or baking them on a later occasion, you can freeze them for 2 hours, then add them to a ziplock bag with a parchment paper in between them. They freeze well for up to 3 months.
For the Florentine sauce:
In a skillet, on medium heat, add the olive oil and the vegan butter, when hot, add the red bell pepper or tomatoes, sauce for 2 to 3 minutes, add the garlic, cook for 40 seconds, add the remainder of the ingredients except from the vegan butter, sautéed until the spinach is soft, add the frozen butter cubes, stir it until the vegan butter is melted and emulsified, turn of the heat and reserve.
For frying the fishless fish filets:
Add the vegetable oil to a skillet, when very hot add the fishless filets, then lower the heat to medium and let them fry for 5 minutes each side.
Remove the filets from the skillet and place them on a cooling hack, reserve.
Plate the filets by adding the sauce to a plate, then place the fishless fish ON TOP of the sauce, never the sauce on top of the fish otherwise the fishless filets will lose the crunchiness and the filets will be too soft.
The fishless filets can be frozen although they cannot be thawed out, once you plan on frying or baking them you remove them from the freezer and add them immediately to the skillet or in the baking sheet lined with an oven rack.
You can also finish cooking them in the oven for 15 minutes ate 375F to ensure the filets are thoroughly cooked, especially if your filets are a bit thicker.