Break the eggs in a bowl and whisk together lightly. In another bowl, mix the dry ingredients together.
Dip the fish fingers in the nut and breadcrumb mixture, then in egg, then in the nut and breadcrumb mixture, and transfer to a paper towel.
Repeat with all the fish. In a skillet, melt the butter over medium high heat and sear the fish fingers, a few at a time, until golden brown. Serve with a slice of lemon, sour cream, chopped shallots and capers.