Tomatillos are prepared in a variety of ways, including blanching, fire roasting and dry roasting. They are also added raw to a number of Mexican sauces and provide a fresh flavour that is comparable to citrus.
Before doing anything to the tomatillos, the husk must be removed as it is inedible. Often a sticky substance remains after removing this husk, but this is easily rinsed off. The skin does not need to be peeled as it softens during the cooking process.
To blanch tomatillos, bring a large pot of water to a boil, and add the tomatillos. Boil for 5 minutes or until soft. Remove them from the water and crush or puree as needed.
To fire roast, use a broiler, a propane torch or an open flame like a grill or a gas stove. Make sure the heat is extremely hot to prevent the tomatillos from turning mushy. Roast, turning gently as needed, until the outside skin is nicely charred all over. To dry roast, place the tomatillos in a heavy cast-iron pan over low heat and roast, turning as needed, for 20 to 30 minutes.
Each cooking method produces a different flavour profile. For example, blanching mellows the flavour of the tomatillos, whereas fire roasting adds a smoky aspect.