Prepare the beef tenderloin by trimming excess fat and tying it with kitchen twine.

Sauté mushrooms and garlic in olive oil until tender.

Add spinach to the sautéed mushrooms and cook until wilted.

Mix cooked mushroom and spinach with sun-dried tomatoes, goat cheese, thyme, salt, and pepper.

Stuff the beef tenderloin with the mixture and tie closed.

Sear the stuffed tenderloin in a hot skillet with olive oil until browned on all sides.

Transfer the tenderloin to a baking dish and pour beef broth around it.

Roast in a preheated oven at 375°F (190°C) until the internal temperature reaches 130°F (54°C) for medium-rare.

Let the beef rest for 10-15 minutes before slicing.

Slice the tenderloin and serve it with the pan juices.