Beef Tenderloin with Creamy Porcini Mushroom Sauce and Roasted Potatoes

First, rehydrate the dried mushrooms by submerging them in boiling water.

Next, melt butter and 2 tablespoons of olive oil in a medium-sized skillet over an intermediate heat setting. Introduce the onion and garlic into the mixture, stirring until they become translucent and tender. Add a beef bouillon cube to the skillet and then pour in the rehydrated mushrooms along with their water. Season the mixture with salt and pepper to taste. Combine 2 tablespoons of cream into the skillet, allowing it to simmer gently for approximately 5 minutes before setting it aside.

Subsequently, immerse whole potatoes in a pan with enough water to cover them. Bring the water to a boil over high heat, and cook for about 5 minutes. Drain the excess water from the pan. Once the potatoes have cooled enough to be handled, cut them in half lengthwise.

Heat 2 tablespoons of olive oil in a medium-sized skillet over an intermediate heat setting, and fry the cut potatoes until they turn golden brown. Season the fried potatoes with salt and thyme to enhance their flavor. Set them aside for later use.

Before proceeding, preheat the oven to 400 degrees F (200 degrees C).

Season beef medallions with salt and pepper. Heat 2 tablespoons of olive oil in a wok or large skillet over high heat, and sear the beef medallions on both sides until they are browned. Remove the medallions from heat and position them in the center of a roasting dish.

Cover the beef medallions with porcini sauce, and arrange the cooked potatoes around them. Cover the dish with aluminum foil to prevent drying out of the meat and potatoes. Roast in the oven for 15 minutes.