Caribou Lichen
Caribou lichen or reindeer moss (Cladonia rangiferina) was traditionally used in the far north as a starvation food and in making alcohol. But reindeer moss has seen a surge in the culinary world with chefs and adventurous cooks. It must be cooked before it's eaten to soften it and reduce its acids. One way is to brine it and then deep fry it. You could also grind it into a powder and boil it in water or milk to make a porridge or use it as a thickener in soups and stews.