Prepare the tenderloin: Preheat your oven to 185 degrees Celsius. Pat the pork tenderloin dry with paper towel to remove excess moisture. This helps achieve better browning and seasoning adhesion.
Season the pork: Rub the entire surface of the tenderloin with olive oil, then season generously with salt, black pepper, garlic powder, onion powder, and dried thyme. Ensure the seasoning is evenly distributed over the entire surface.
Roast the tenderloin: Place the seasoned pork tenderloin on a baking sheet lined with baking paper or in a roasting pan. Roast in the preheated oven for 20-25 minutes, or until the internal temperature reaches 63 degrees Celsius when measured with a meat thermometer in the thickest part of the meat.
Rest the pork: Once cooked, remove the tenderloin from the oven and transfer it to a cutting board. Cover loosely with aluminium foil or a clean kitchen cloth and let it rest for 8-10 minutes. This resting period allows the juices to redistribute throughout the meat, ensuring maximum tenderness and moisture.
Make the Dijon cream sauce: While the pork is resting, prepare the sauce. In a medium skillet over medium heat, melt the butter or heat the olive oil. Add the minced garlic or garlic flakes and sauté for 1-2 minutes until fragrant, being careful not to burn it.
Build the sauce: Stir in the Dijon mustard, mixing it well with the garlic and butter. Add the heavy cream, capers, chicken stock, salt, and black pepper. Whisk everything together until smooth and well combined.
Simmer the sauce: Allow the sauce to simmer gently for 5-7 minutes, stirring occasionally, until it thickens slightly and coats the back of a spoon. If the sauce becomes too thick, add a splash more chicken stock or cream to reach your desired consistency.
Slice and serve: Slice the rested pork tenderloin into medallions about 2 cm thick. Arrange the slices on a serving platter or individual plates. Drizzle generously with the warm Dijon cream sauce and garnish with freshly chopped parsley or thyme.