Preheat your oven to 400°F (200°C).

In a small bowl, combine crushed green peppercorns, crushed fennel seeds, salt, and black pepper.

Rub the veal tenderloin all over with the olive oil, then coat it evenly with the peppercorn and fennel mixture.

Heat a large oven-safe skillet over medium-high heat. Add the veal tenderloin and sear it on all sides until browned, about 3-4 minutes per side.

Transfer the skillet to the preheated oven and roast the veal for 20-25 minutes, or until it reaches an internal temperature of 145°F (63°C) for medium-rare. Remove from the oven and let it rest for 10 minutes.

While the veal is resting, prepare the gravy. In the same skillet, add the unsalted butter over medium heat. Add the chopped onion and garlic, cooking until softened, about 3-4 minutes.

Stir in the smoked tomatoes and cook for another 2-3 minutes.

Pour in the beef broth and bring to a simmer. Allow it to cook for about 5 minutes, reducing slightly.

Lower the heat and stir in the heavy cream, chopped thyme, and Dijon mustard. Allow the sauce to simmer for an additional 5 minutes, stirring occasionally, until it thickens slightly.

Slice the rested veal tenderloin into medallions and serve topped with the rich smoked tomato gravy.