Dice the bacon. Chop the herbs and shallots. Put all of the ingredients for the topping in a mixer and whizz until the mixture is creamy. Place the filling on a sheet of parchment paper and roll up to form a small salami. Place in the fridge to harden. Once chilled, cut the roll into 4 slices.
Salt and pepper the fillets. Brown them in a pan in the clarified hot butter. Cook them rare. Remove from the pan, leave to cool and cover with slices of the topping.
Discard the cooking liquid from the pan and pour in the wine or water. Let the liquid evaporate by two thirds. Add the tomato sauce and the brown roux or concentrated broth. Reduce by one third. Strain through a sieve. Emulsify with the cold butter in small flakes. Place the filets in a hot oven for 2-3 minutes. Pour the sauce on the bottom of the hot serving-plates and lay the tournedos on top. Serve.