Add the shiitake dashi, mirin, and light soy sauce to a small saucepan and heat to a gentle simmer.
Get the potato starch slurry ready by stirring it to eliminate any clumps.
Gradually add the potato starch slurry into the dashi mixture stirring continuously to avoid clumping. Bring to a gentle boil and within a minute or so, the mixture should be noticeably thicker.
Once thickened, remove from heat and cover.
To make the vegetables
Using a large pan on medium heat, add the oil and cook the renkon and mushrooms for 1-2 minutes.
Add in the rest of the vegetables and cook for 4-5 minutes until softened. Stir
occasionally, allowing them to brown slightly.
Once the vegetables have softened, add all the ‘an’ sauce to the vegetable pan and mix the vegetables into the sauce.
Remove from heat.
Place one serving of brown rice into a bowl and pour the vegetable ‘an’ sauce over the rice. Use one generous cup of rice (or 1 bundle of udon noodles) and one generous cup of vegetables with an sauce per person.
Top with desired toppings and enjoy!
Other vegetables that work well in this dish are onion, shredded carrots, okra, baby corn, bamboo shoots, eggplant, zucchini, tomatoes, spinach or mizuna. Basically, anything that you’d use in a stir fry would go well with the ‘an’ sauce.
Use any leftover vegetable ‘an’ sauce as a side dish on its own or to season other foods such as block tofu.