Combine the first eight ingredients in a large mixing bowl. Fold in egg, crawfish tails, & rice. Add 1⁄2 cup breadcrumbs to tighten up the mixture. If necessary, refrigerate until mixture holds its shape (30 mins. - 1 hr).
Form into 8-10 patties, then gently coat all sides with remaining breadcrumbs.
Preheat a cast iron (or heavy bottomed) pan over medium-high heat, then coat the bottom with oil. Once oil is heated, shallow fry patties in batches, until golden brown. Set aside on paper towel lined plate or keep warm in the oven on a cooling rack lined pan.
Serve over a bed of arugula and top with a squeeze of lemon, remoulade sauce, sliced green onions & a sprinkle of cajun seasoning.