Lay clean oyster mushrooms on a paper towel (or tea towel) and sprinkle them with salt. Turn them over and sprinkle the other side with salt as well.
Let the mushrooms sit for 30 minutes to draw out some of the moisture.
Make vegan buttermilk
Put 3/4 cup of plant-based milk in a shallow bowl with 1 teaspoon of apple cider vinegar and 1 teaspoon of hot sauce. Give it a stir and let it sit for at least 5 minutes to let it thicken.
Prepare your breading
In a separate bowl, mix 1/3 cup flour, 1/4 cup cornstarch, 1/4 cup cornmeal, 1 tsp oregano, 1 tsp creole seasoning, 1/2 tsp garlic powder, 1/2 tsp onion powder, 1/2 tsp paprika,1/4 tsp black, and white pepper.
Once the mushrooms have sat for about 1/2 hour, place them in a colander and rinse the salt off of them, then pat them dry with a paper towel.
Heat oil to 370° F (187° C) either in a deep fryer or in a pan. (Use a thermometer or test a small mushroom to make sure you have the correct temperature. It should bubble as soon as it hits the oil and become golden brown after about 2-3 minutes of cooking.)
Bread the mushrooms
Dip the washed and dried mushrooms into the milk solution and then into the flour mixture and coat it well. Then quickly dip the mushrooms back into the milk solution and coat a second time with the dry flour mixture. Set aside until you have about 5-6 mushrooms ready to fry.
Place the mushrooms in the hot oil and cook for about 2-3 minutes until the bubbling slows and they become golden brown.
Take them out of the oil with a skimmer basket or tongs and cool them on a paper towel.
Repeat until all of the mushrooms are cooked.
Serve hot with your favorite dipping sauce.
Notes
You can omit the process of salting the oyster mushrooms if you want, but I find the taste and texture to be much improved with this method. If you don't salt them first, the moisture from the mushrooms gets the batter soggy quickly.
The cornstarch in this recipe is key to making the coating crispy and the cornmeal is key to giving it texture. I don't recommend omitting those ingredients.
For a lighter coating, only dip the mushrooms in the milk and seasonings 1 time instead of twice.