Roux, the classic thickener made from fat and flour, feels like a seasonal recipe. I make it more often in the winter than any other time of year, thanks to dishes like mushroom soup and macaroni and cheese.
Some cooks feel that roux is outdated, preferring to use other methods to thicken sauces and soups. I disagree. I love having options in the kitchen and a roux is sometimes just the thickener--I can't imagine making gravy without it. The recipe below is just a guide. Use it when you want to make a silky white sauce or gravy. In fact, you probably already have recipes that call for roux; they just might not refer to it as a "roux." Anytime you see fat and flour cooked together in a recipe, simply replace the wheat flour with sweet rice flour and follow the recipe as written.
Unlike other gluten-free recipes, you don't need to substitute the wheat flour used in roux with several gluten-free flours. Sweet rice flour, ground from glutinous rice, makes a velvety gluten-free roux and nicely replaces wheat flour measure for measure.
Classically roux uses clarified butter as its fat. Since I rarely have clarified butter in the kitchen, I use either regular butter or olive oil. The flexibility of gluten-free roux allows you to use whatever fat fits in your diet, from butter to lard to liquid vegetable oil. Just remember to use an equal amount of fat to sweet rice flour.
To prepare a roux, heat the fat in a heavy-bottomed saucepan over medium-low heat. (If using a solid fat, allow it to melt before adding the sweet rice flour. For a liquid fat, like olive oil, heat the oil until it just begins to shimmer. No matter what fat you're using, you don't want it too hot when adding the sweet rice flour.)
"the roux darkens and takes on a reddish hue"
Once the fat is heated, add the sweet rice flour all at once, and begin whisking the mixture with a balloon whisk. Roux in French means "red" and, if you are making your roux with butter, this is a good visual. During cooking, the roux darkens and takes on a reddish hue thanks to the milk solids in the butter. If you are making a roux with oil, however, it does not darken when cooked. The roux will remain pale, so keep your eye on the timer and cook the roux for five minutes. After five minutes of cooking, the sweet rice flour loses its raw flavor, which is the goal.
To make a sauce or gravy, whisk liquid (milk or stock) into the cooked roux in a slow and steady stream. Allow the roux to absorb the liquid as you add it to the saucepan and adjust the sauce's consistency as desired.
- For the Roux:
- 1 ounce (two tablespoons) butter, olive oil, or other fat
- 1 ounce (about two tablespoons) sweet rice flour
- For the White Sauce:
- 1 1/2 cups milk, room temperature
- salt and pepper to taste
- 1/2 small onion, diced and sautéed until soft
In a small (2 quart) heavy-bottomed sauce pot, melt butter over medium-low heat. Add sweet rice flour.
Cook, whisking constantly, for five minutes. If using butter, roux will darken and become reddish; if not, roux will remain pale.
For a white sauce. Add milk, in a slow and steady steam. Whisking constantly, heat sauce until it thickens, about three minutes. Season to taste.