In a large skillet, heat extra virgin olive oil over medium-high heat. Add the pork tenderloin, season with salt and black pepper, and sear on all sides until browned, about 3 minutes per side. Remove from the pan and set aside.
In the same skillet, melt the unsalted butter and add the chopped shallot. Season lightly with salt and black pepper, and cook for about 2 minutes until the shallot softens. Stir in the minced garlic and let it cook for 30 seconds, just until fragrant. Add the sliced cremini mushrooms and sauté for about 4 minutes, letting them turn golden and release their flavor.
Pour in the chicken broth and scrape up any browned bits from the bottom of the pan. Let the mixture simmer for about 5 minutes. Stir in the cream and continue simmering gently for another 2 minutes until the sauce begins to thicken.
Slice the pork, return it to the skillet, and cook for 3 minutes until the sauce thickens and the pork is cooked through.
Serve with the creamy mushroom sauce and boiled potatoes.
Notes
Rest the Pork Before Slicing: I always let the pork sit for a few minutes before slicing so the juices stay inside.Browning the Mushrooms: I find they brown best when I leave them alone in the pan instead of stirring too much.Creamy Consistency: I like to simmer just until the sauce lightly coats the back of a spoon; it feels perfectly silky.