Bring a large pot of salted water to the boil. Drop in the beans and
cook for about 5 minutes. When perfectly done, drain them in a colander.
To make the marinade, mix the chopped shallot or onion in a bowl with
the herbs, mustard, vinegar and 4 tablespoons of extra virgin olive
oil. Season with salt and pepper to taste, then add the hot cooked
beans and toss. Put to one side to allow the beans to cool down and
take on all the fantastic flavours.
Place the beef fillet on a chopping board and season it all over with
salt and pepper. Run the thyme sprigs under hot water for a few seconds
– this will help to release their fragrant oils. Strip the leaves from
the stalks and chop them up roughly. Sprinkle the thyme over the
fillet, then roll the meat around the chopping board so that any excess
seasoning and herbs stick to it.
Get a heavy frying pan very hot and add a splash of oil, followed by
the beef fillet. Fry for 1 minute only, turning it every few seconds to
sear and encrust all the lovely flavourings on to it. Take the meat out
of the frying pan and put it on to a plate to rest for a minute. (Once
seared, you can serve straight away or you can keep the meat covered on
a plate until needed. I prefer not to keep it in the fridge.)
Using a sharp knife, now slice the seared fillet this thick: ——. Lay
each slice on a board and flatten as much as you can by pressing down
on them with the side of a chopping knife – it works a treat. Lay two
or three slices out flat on each plate. Season again lightly and place
a pile of beans on top, spooning over some of the marinade. Sprinkle
over any leftover herb leaves and drizzle with some good extra virgin
olive oil.