Preheat your oven to 400°F (200°C). Season the beef tenderloin generously with salt and pepper.

In an oven-safe skillet, heat the olive oil over medium-high heat. Once hot, add the beef tenderloin and sear it on all sides for about 2-3 minutes until beautifully browned.

Transfer the skillet to the oven and roast the beef for about 10-12 minutes for medium-rare doneness (130°F to 135°F). Let it rest for 5-10 minutes before slicing.

While the beef rests, slice the baguette into thin slices and brush both sides lightly with olive oil. Place on a baking sheet and toast in the oven for about 5-7 minutes until golden brown.

In a saucepan, combine the heavy cream, minced garlic, and grated parmesan cheese over medium heat. Stir until the cheese melts and the sauce thickens slightly (about 3-5 minutes). Season with salt and pepper to taste.

Slice the rested beef tenderloin into thin pieces and top each crostini with a slice of beef, followed by a generous drizzle of the parmesan cream sauce. Garnish with fresh herbs if desired. Serve warm.