Brown the tenderloin pieces in some oil in a tall, ovenproof pan, then remove to a warm platter. In place of the tenderloin pieces add the chopped parsley and sauté for 6-7 minutes, stirring constantly. Once the vegetables have browned, add the mushrooms along with the garlic, continuing for other 5-6 minutes, then add the wine and stock one at a time. Simmer the sauce for 10-12 minutes, then add the browned pieces of moss, the chopped sage and rosemary and the spices.

Preheat the oven to 160°C. Once you have added the pieces of moss, cover the pan with a lid and place it in the oven. Bake for 1-1 ½ hours, until the tenderloin pieces are tender and the sauce has reduced slightly, then add the chopped parsley.

Fry the remaining leek strips and mix with mashed potatoes.

Serve the pieces of moss placed on mashed potatoes and topped with the wild mushroom sauce.