Season fillets with salt and pepper. Heat a heavy saute pan over medium high heat. Coat edges of fillet with a thin layer of mustard, approximately 2 tablespoons. Dredge edges of filet in herbs to coat evenly. Sear fillet, 4 to 6 minutes per side, depending on the thickness of the meat.
Remove cooked fillet. Lower heat to medium. Add shallots and saute until translucent. Deglaze pan with white wine. Add 2 tablespoons mustard. Reduce wine to consistency of a rich sauce. If desired, remove the pan from the heat and whisk butter into the sauce. Serve immediately.