Canna tubers are an edible root with a sweet flavor. Also referred to as arrowroot, canna tubers are high in starch and are a staple food in some Third World countries, such as Vietnam. Canna tubers are drought, shade and disease resistant, making them an ideal starch for backyard gardens. The simplest way to cook these brown starch roots is in the oven, similar to a regular baked potato.
Preheat the oven to 400 degrees.
Scrub the canna tubers with a potato brush under running water until any dirt particles are removed.
Poke the canna tubers with a fork at least six times along the cannas' surface.
Wrap the canna tubers in tin foil.
Bake the canna tubers for one hour.
Remove the tubers from the oven and set aside for 10 minutes, to allow the juices time to redistribute.