The Tomatillo (tohm-ah-TEE-oh)
*Note: This blog post from Smithsonian Gardens’ Horticulturist Joe Brunetti originally appeared as part of the National Museum of American History’s “O Say Can You See?” Blog as part of NMAH’s celebration of Hispanic Heritage Month.
“What is a tomatillo?” “What sort of recipes use tomatillos?” “What do they taste like?” These are just a few of the questions I get asked when I show visitors the tomatillos growing in the Victory Garden at the National Museum of American History. Simply put, tomatillos are small fruits ensconced in a papery husk. These beauties belong to the nightshade family – yes, the same nightshade family that contains the usual scene-stealers – tomatoes, potatoes, eggplants, tobacco and even petunias. The tomatillo is like the distant cousin that doesn’t make it to the family get-togethers, and it’s high time you two got to know each other.
Tomatillos (Physalis ixocarpa) are a summer annual originating from Mesoamerica and therefore grow best under similar conditions as a tomato plant. In the spring, when the danger of frost is no longer at hand, plant tomatillos in full sun and in rich organic soil. Provide a supporting structure like a tomato cage as it grows. A ripe tomatillo looks and feels much like an un-ripened tomato – typically firm, with a green and/or yellow hue. They vary in size from one inch in diameter to plum-sized. You want to harvest your tomatillos when the husk has not browned and the fruit is still firm to the touch.
Speaking of the husk (which most people associate with corn), it is botanically known as the calyx. Think of it as a paper-like shield protecting your produce from ravenous varmints. Thank you calyx! When this shell is peeled off of the tomatillo a sticky resin is left on the skin, but it washes off easily.
The taste of a tomatillo combines the heartiness of a tomato with the citrus zing of a lime. It is sure to get your taste buds dancing. The texture is like an under-ripe, spongy tomato. Trust me, it’s cool.
Tomatillos have been cultivated for millennia and were a staple food in ancient Mayan and Aztec communities. In fact, the Aztecs are credited with domesticating the tomatillo. To this day, this peculiar fruit is a constant component of Mexican and Guatemalan diets. Traditionally, tomatillos are combined with chili peppers to make sauces, with the coolness of the tomatillo balancing out the hot flavor of the pepper. Have you eaten salsa verde (green sauce)? Well then, you’ve probably eaten tomatillos since they are typically the main ingredient in salsa verde. Other uses for the tomatillo include chopping them and adding them to salads and salsas, or pureeing them into gazpacho and guacamole. Less commonly, but still worth mentioning, tomatillos are used to flavor rice and tenderize red meats.
Right now in the Smithsonian’s Victory Garden grows a tomatillo that demands attention. Instead of the familiar green, this variety’s fruit and husks are tinted midnight purple. Come by sometime and have a look!
Tomatillo Tortilla Soup with Ground Bison
Makes 4 – 6 servings. Prep time: 15 minutes. Cook time: 20 minutes)
1 lb. ground bison (or any other ground meat or meat substitute)
1 red onion, diced
A dozen tomatillos, de-husked, rinsed, and cut into 1-inch pieces
2 cups chicken broth
1 15-oz can diced tomatoes
1 15-oz can black beans, rinsed
1/4 tsp cayenne pepper
1 tsp chili powder
1 tsp ground cumin
1 tsp dried oregano
Salt and pepper to taste
Sour cream or Greek yogurt with a splash of lime juice (that’s what I always use!)
Cheddar or Mexican blend cheese, for garnish (plus some on the bottom of your bowl, of course)
Tortilla chips, broken
In a soup pot, heat about 1 Tbsp of olive oil over medium high heat. Add the ground bison, reducing the heat to medium after about two minutes of browning. Cook through.
Meanwhile, put the tomatillos and about 1 cup of the chicken broth in a blender. Blend thoroughly, until all of the tomatillos are pureed.
Add the tomatillo mixture to the browned bison. Add the diced tomatoes, black beans, remaining, chicken broth, and spices. Season with salt and pepper.
Bring to a boil, then cover and reduce the heat to medium low. Cook for about 20 minutes, stirring occasionally and adding either more broth or water as necessary, so it keeps the consistency you want. Taste it a couple times during the cooking process so you can adjust the seasonings if you want.
To serve, sprinkle a little cheese in the bottom of the bowls, then add the soup, then top with more cheese, tortilla chips, and sour cream/Greek yogurt-lime juice mixture. Enjoy!