First I prepare the meat, for this, I will slice the ribeye steak into strips, transversely along the length of the fibres. Put the meat in a bowl where we season it with sea salt and freshly ground pepper.
Peel the onion and finely chop it, do the same with the garlic. Clean the mushrooms from the skin, cut them in half and then sliced them into thin slices,
In the Dutch oven pot, heat four tablespoons of extra virgin olive oil. When the oil is hot, it starts to smoke, put the half of meat the strips in the pot to fry. Fry the meat strips for a minute, turning them halfway through or when they have acquired a golden crust. Take them out in a bowl and leave them there for a while. Repeat this with the rest of strips.
In the same pot without cleaning it, melt a tablespoon of unsalted butter and sauté the chopped onion and chopped garlic. Season with sea salt and left it to sauté for a minute stirring, after which add the sliced mushrooms. Season with freshly ground pepper and let it simmer for about five minutes under the lid.
Sprinkle two tablespoons of wheat flour on top, stir and let it one minute to fry. Add the mustard, sea salt, beef concentrate and simmer for about five minutes. Pour the single cream, mixing with a wooden spoon until it is completely incorporated. Let it simmer for another five minutes.
Add the pre-fried meat strips, the chopped parsley and turn off the heat.
Serve immediately with the favourite side dish, in our case polenta, some pickles for acidity and then a large glass of cold beer.