Subtle, delicious and perfectly balanced flavors is what the best filet mignon needs as a sauce. With hundreds of ways to prepare this cut of meat, this one stands out because of its simplicity. Spicy mustard and earthy herbs pair with the crème fraiche for a silky, aromatic, lip smacking sauce. This dinner is so comforting it will have you thinking back to your childhood. Serve the entire thing over a sizzling pile of mashed potatoes for an even homier feel.