Lightly salt and pepper one side of each steak, then pepper the other side. Top each steak with a bacon slice and one sage leaf, securing with a toothpick.
Heat fat in a large pan over medium-high heat. Fry the steaks for 2-3 minutes on each side until cooked through (internal temperature 63°C / 145°F).
Transfer the steaks to a plate, wrap loosely in aluminum foil, and keep warm in a 50°C (122°F) oven.
Pour the 200 ml vegetable stock into the pan and bring to a boil over medium-high heat. Add the 1 teaspoon brandy and the finely chopped remaining sage leaves. Reduce for about 2 minutes.
Stir in the 100 ml cream and the 1 tablespoon plant cream. Season with pepper and adjust salt to taste. Bring to a boil and boil for 1 minute.
Reduce heat to low. If needed, thicken the sauce with a light sauce thickener.
Return the steaks to the pan, cover with a lid, and let them warm through for 1-2 minutes.