How to make it
Add the mayonnaise, cilantro, lime zest, lime juice, cumin, and hot sauce to a food processor. Blend until combined. Set the cilantro aioli aside.
Add the all purpose flour to a shallow dish. Combine the eggs and Lee Kum Kee Panda Brand Oyster Flavored Sauce in a separate shallow dish. Add the panko, salt and pepper, to another shallow dish. Mix to distribute the seasoning.
Pour the vegetable oil into a pot so that it’s about 2” deep. Bring the vegetable oil to 350˚F.
While the oil heats, coat the Portobello mushrooms in the flour. Dust off any excess flour. Then dip the mushrooms into the egg mixture until all of the flour has been absorbed. Allow any excess egg to drip off. Completely coat the mushrooms in panko.
When the oil is hot, add in the mushrooms, working in a few batches at a time. Fry until golden brown, about 2-3 minutes. Flip the mushrooms over and fry for another 2-3 minutes until the other side is golden. Remove the mushrooms from the oil and allow them to drain on a plate lined with paper towels.
To assemble the mushroom burgers, place a handful of arugula onto the bottom brioche bun. Place the mushroom on top. Add a few spoons of the cilantro aioli onto the mushroom. Layer on the tomatoes and red onion. Place the top brioche bun on top and enjoy!