Preheat the oven to 220'C.
Cut the skirt steak into 150g steaks.
Finely dice the garlic and chop the flat parsley.
Use a sharp knife to make incisions in the beef . Insert the sage into the incisions and season with salt.
Heat a frying pan and add a little olive oil. Colour both sides of the fillets and then remove from the pan. Allow to rest for at least 5 minutes before placing in the oven and cook for 5 to 8 minutes depending on the thickness of the steak.
Wash all of the mushrooms and trim if necessary. Heat a pan, add olive oil and cook the mushrooms in batches making sure not to overcrowd the pan. Make sure they are a nice golden brown colour. Seaason with salt and pepper each time you cook a batch. Finish with the garlic and the chopped parsley.
Serve the beef on a bed of mushrooms.
«Vary the mushrooms according to taste, season and availability.»