For the pickled red cabbage: Put the red cabbage in a plastic container and set aside.
Meanwhile, in a small nonreactive saucepan, combine the rice vinegar, white vinegar, sugar, red chile flakes, garlic and 5 ounces water. Bring to a simmer over medium-high heat. Pour the mixture over the cabbage, cover with a lid and refrigerate for 24 hours.
After 24 hours, drain the cabbage and store in the refrigerator for up to 3 days.
For the sriracha mayonnaise: In a medium bowl, combine the mayonnaise, chili sauce and lemon juice and stir to fully incorporate. Refrigerate until ready to use.
For the crab cakes: Heat a flat griddle pan over medium-high heat.
In a large bowl, combine both kinds of crabmeat with the breadcrumbs, mayonnaise, dill, tarragon and a pinch of salt and pepper until well incorporated. Shape the mixture into 4 equal patties.
Grill the patties on the hot griddle pan until golden brown and cooked through, 3 to 4 minutes per side.
For the sandwich assembly: Butter both halves of each brioche bun and place on the griddle pan. Toast until the buns are golden brown, about 1 minute.
Spoon 1 tablespoon of the sriracha mayonnaise on both halves of each brioche bun. Add a handful of arugula on the bottom halves and top with a crab cake. Top each crab cake with a handful of pickled red cabbage, followed by 2 tablespoons green onions. Serve immediately.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Sunbird Kitchen, Cape Cod, MA