Ingredients
Buttermilk Soak
- 1 lb Italian oyster mushrooms from KC Mushroom Co., torn into 4 large clusters
- 1 1/2 cups buttermilk
- 1 tbsp hot sauce
- 1 tsp kosher salt
Seasoned Dredge
- 1 1/2 cups all-purpose flour
- 1/2 cup cornstarch
- 2 tsp kosher salt
- 1 tsp black pepper
- 1 tsp smoked paprika
- 1 tsp garlic powder
- 1 tsp onion powder
- 1/2 tsp cayenne pepper
For Frying
- neutral oil for deep frying, about 4 cups
- Sandwich Sauce
- 1/2 cup mayonnaise
- 2 tbsp dill pickle juice
- 1 tbsp Dijon mustard
- 1 tsp hot sauce
- 1 tsp honey
To Build
- 4 brioche burger buns toasted
- 4 leaves butter lettuce
- 12 dill pickle chips
- 1/2 small red onion thinly sliced
Instructions
- Whisk the buttermilk, hot sauce and salt together in a wide shallow bowl. Add the mushroom clusters and press down so they're submerged. Soak for 20 minutes at room temperature — the buttermilk tenderizes the mushrooms and gives the flour something to cling to.
- While the mushrooms soak, whisk all the dredge ingredients together in another wide bowl. In a small bowl, whisk all the sandwich sauce ingredients together and refrigerate.
- Heat about 2 inches of oil in a heavy pot or Dutch oven to 350°F. Use a thermometer — temperature is everything in deep frying. Line a wire rack over a baking sheet to drain the fried mushrooms.
- Lift one mushroom cluster from the buttermilk and let the excess drip off. Press into the seasoned flour, packing it firmly into every crevice. Lift, dip briefly back into the buttermilk, then return to the flour for a second coat. This double-dredge is what creates the craggy, deeply crisp coating.
- Lower the breaded cluster carefully into the hot oil and fry 4 to 5 minutes, turning once, until deep mahogany brown all over and the coating crackles to the touch. Don't crowd the pot — work in batches if needed and let the oil come back to 350°F between each.
- Transfer to the wire rack and sprinkle immediately with a pinch of salt. Repeat with the remaining clusters.
- Build each sandwich: smear sauce on both halves of the toasted bun, layer lettuce on the bottom, top with a fried mushroom cluster, then pickles and red onion. Crown with the top bun and serve immediately while the coating is still crackling.
Notes
From the farm: Italian oyster clusters with a strong, intact base hold together best for this preparation. If your clusters are smaller, you can fry two together as a single sandwich filling.
Tip: The double-dredge is non-negotiable for proper crunch. A single coating goes soggy fast; the second layer builds the craggy, restaurant-style coating that defines this sandwich.
Make ahead: The seasoned dredge mixture and the sandwich sauce both hold for a week. Fry the mushrooms just before serving — they're at their best in the first 20 minutes out of the oil.
