Everyone seems to be into fermented foods these days, and I am no different. I love anything umami or pickled and fermented foods tend to be foods with these complex flavor profiles.
What are fermented foods?
Fermented foods are basically food products made/altered by microbes (often bacteria or yeast). The fermentation process has been used for years to help preserve foods. Common examples of fermented foods include: wine and beer, yoghurt, kimchi, coffee, and sauerkraut.
There is some evidence, although still somewhat contentious, that links consumption of fermented foods with improved health outcomes including: weight maintenance, reduced risk of cardiovascular disease, improved glucose metabolism, improved mental health…(1) Clearly, more research should be done, but if you enjoy fermented foods (like me), than they can be an awesome addition to many standard meals.
Miso is pretty high on my list of fermented foods. Miso is often made from soy beans, salt, rice, water, and Aspergillus Oryzae (a type of mold). Miso typically goes through a double fermentation process. A koji is first created by adding the mold cultures to a steamed grain mixture, which breaks down the starch into simple sugar molecules by an enzyme known as amylase. The koji is then combined with the soybeans and salt. Specific strains of bacteria are then often added, which convert the simple sugar molecule into lactic acid, acetic acid, other organic acids, and alcohol, which gives it its unique aroma and flavor.(2)
It can come in many varieties, colors, and flavors, but for this recipe I used a softer sweeter white miso in the sauce.
Miso Sweet Potato, Kale, and Tofu Stir Fry
- 1/2 onion
- 1 tsp. salt
- 2 tbs. extra virgin olive oil ( or whichever oil you prefer)
- 12 oz. (about 1.5 cups) thinly sliced sweet potato strips (I buy the sweet potato ribbons from Trader Joe’s for quicker prep)
- 2 cups kale
- 1 package firm tofu
- 1 Tbs. Soy Sauce
- 2 Tbs. White miso paste
- 2 Tbs peanut sauce
- Juice of 1 lime
Heat oil on medium-low in a large pan or wok. Finely dice onion, and add to pre-heated pan with salt. Cook on medium- low until onion is soft and translucent (approximately 10 minutes). Add sweet potatoes and cook over medium heat stirring occasionally until soft and fragrant.
While onions and potatoes are cooking prepare the sauce by whisking ingredients together in a small bowl until they form a smooth thick sauce.
Add half of the sauce to your stir fry and stir until mixed. Then add the kale and tofu and cook stirring slowly until kale is soft (wilted) and tofu is cooked through (another 5-8 minutes). Top with the rest of the sauce and mix until combined.
Serve plain or over brown rice.
For more on Fermented Foods, check out:
- Gille D, Schmid A, Walther B, Vergères G. Fermented Food and Non-Communicable Chronic Diseases: A Review. Nutrients. 2018;10(4):448. Published 2018 Apr 4. doi:10.3390/nu10040448
- Miso. Science Direct. https://www.sciencedirect.com/topics/food-science/miso
- Wilson, L.A., et al., Japanese Soyfoods: Markets and Processes, MATRIC, Iowa State University, Ames, IA, 1992.