Preheat the oven to 350°F. Lightly butter a 10-inch gratin dish or an 8-inch square baking dish.
Steam, until crisp-tender, about 5 minutes:
11⁄4 pounds yellow squash...
When you live as far out in the country as we do, one of the ways of making sense of your surroundings is by learning the common names of plants. Redbud, white oak, pokeweed, mountain mint. Evening walks turn into botanical excursions, and you start to notice the change of the seasons by what plants are in bloom.
You also start to develop an interest in wild edibles. This is something of a tricky subject, given the horror stories of poisonous plants or of edible plants with poisonous lookalikes, those wolves in sheep's clothing of the plant world. But there are some plants that are very easy to identify safely.
Cattails, for instance. Even those of us who have never set foot outside a city can probably identify a cattail. But did you know that cattails are edible? Everything from the pollen to the roots of the cattail plant are edible. The trick is knowing when to harvest them. Another wild edible, and one that we would like to focus on today, is the sassafras tree.
For decades (perhaps even centuries), the roots of the sassafras tree have been brewed into a delicious tea. In the '60s, it was banned for commercial use because it contains safrole oil, which is considered a carcinogen. Have no fear, though! You would have to drink gallons of the stuff every day for it to be a serious problem. Besides, today we will be focusing on the leaves of the plant, which are not harmful in the least.
Sassafras leaves, when dried and ground into a powder, become a key ingredient for gumbo--filé powder. Filé powder thickens soups and stews, turning them into unctuous gravies rather than watery broths. You can buy filé powder, but it's so easy to make that we encourage you to give it a try.
Before you can make filé powder, you have to first locate a sassafras tree. These trees are distinctive for one principal reason--there are three different leaf shapes on the same tree. See the image above for clarification. One of the shapes is an unlobed oval (cup your hands with only the tips of your fingers and the heel of your hands touching--that's the shape of this leaf). The second shape looks like a mitten--two lobes, one being much larger than the other. The third leaf shape has three lobes (I call this a "turkey foot" leaf).
Never collect plants from the side of the road unless there is very little traffic on the road and you are absolutely sure that it has not been sprayed. Sassafras trees are ubiquitous in most of the eastern United States and can be found in sunny, well-drained areas. If you crush a leaf or a small twig between your fingers, you should notice a citrusy smell.
Gather several leaves and wash and dry them. Place them in a single layer on a plate lined with a paper towel. Microwave them in 30-second bursts until they are fully dried (they should crumble easily). Place them in a spice grinder and grind until they are reduced to a fine powder. There may be some large bits or fibers left in the powder. Simply run the powder through a sifter or a fine sieve to remove these larger bits.
Filé powder can be used in soups and stews, most notably in gumbo. It imparts some flavor, though it is mostly used as a thickener. There are as many variations on gumbo as there are cooks. Some recipes call for a sprinkling of filé powder, some for a much larger amount, and some for no filé powder at all, using a roux and/or okra as a thickener instead. The Joy of Cooking says that fileé powder has a tendency to become stringy when heated, so be sure to add the powder once the gumbo is removed from the heat. As filé powder does not reheat well, only use it to thicken the portion of gumbo that is to be served immediately.