The day before, season your steaks with salt and leave them uncovered in the fridge overnight. This will allow the salt to penetrate the meat while drying the surface, which results in a better crust. Pull the steaks out about 30 minutes before cooking.

Put a large pan on high heat. Rub a little veg oil on the steaks and season them with a few grinds of black pepper. Sear the steaks in the pan for 3 to 5 minutes per side, or until they're cooked to your liking. Remove the steaks to a plate to rest, tented loosely with some foil.

Turn the pan down to medium and add the shallot. Fry for about 1 minute, then deglaze with the chicken stock. Let simmer another minute, then add the spinach. Once the spinach has wilted, add the cream and mustard. Break the gorgonzola into small chunks and stir it into the sauce until melted. This should only take a minute. Taste, then season as needed. Spoon the sauce over the steak before serving.