Chop the cattail shoots into chunks with a sharp knife.
Rinse the chopped cattail chunks with distilled white vinegar or warm water to remove any bacteria or debris that was attached. Rinse in cool water after cleansing with distilled white vinegar.
Melt the butter or cooking oil in a skillet.
Place the chunks of cattail stalks, onion, and garlic in the skillet.
Stir fry over high heat for about five minutes.
When about 1 minute is left for stir frying, drop in the chopped tomato (optional).
Remove the skillet from the heat, and enjoy eating the wild stir fry as soon as it has cooled enough to consume.