Preheat oven to 160˚C. Salt the tenderloin, pepper and fry in a grill pan until half cooked. Transfer the meat to the oven and cook for 5-7 minutes.
Pour the cream into a saucepan, bring to a boil and reduce by 1/3.
Fry hazelnuts in butter until golden brown and transfer to a blender bowl. Pour in 2 tbsp. l. cream and blend until smooth. Mix with mashed potatoes.
Put the meat on plates, next to the mashed potatoes. Drizzle with cream sauce and garnish with confit tomatoes.