For the Fried Mushrooms
Neutral oil for frying, such as vegetable or canola
1 large cluster of oyster mushrooms, about 250 grams or 8 3/4 ounces
2 cups all-purpose flour, divided
1 teaspoon fine salt
1 teaspoon freshly ground black pepper
1/2 teaspoon smoked paprika
1/2 teaspoon garlic powder
1/4 teaspoon baking powder
1 large egg
1/2 cup water
For the Cabbage Slaw
2 tablespoons neutral oil
1 tablespoon apple cider vinegar
1/4 teaspoon fine salt
1/4 teaspoon freshly ground black pepper
2 cups thinly sliced green cabbage
1/2 apple, preferably Honeycrisp, cut into thin matchsticks
1 small carrot, grated
For the Spicy Aioli and To Serve
1/3 cup mayonnaise
1 tablespoon sriracha
4 brioche buns
Pickles for serving, optional
Gather the ingredients. Line a plate or rimmed baking sheet with paper towels.
Heat 2 inches of neutral oil in a large pot over medium until the temperature reads 350 F on a kitchen thermometer.
Gently tear 1 large cluster of oyster mushrooms into 4 pieces, breaking off at the stem end so that the mushrooms remain in clusters.
Place 1 cup of the all-purpose flour in a shallow medium bowl.
Combine the remaining 1 cup all-purpose flour, 1 teaspoon fine salt, 1 teaspoon freshly ground black pepper, 1/2 teaspoon smoked paprika, 1/2 teaspoon garlic powder, and 1/4 teaspoon baking powder in a second shallow bowl.
Whisk to combine 1 large egg and 1/2 cup water in a third shallow bowl.
Once the oil is hot enough, dredge 2 of the mushroom clusters in plain flour, then egg wash, then seasoned flour, turning to coat in each mixture until completely coated.