Dashi made of Vegetable Scraps. You can use celery, carrots, onions, cabbages, garlic and other available leftovers. Use various vegetable as many as you want.
Pour a teaspoon of cooking sake/cooking liquor and the scraps of vegetables into the pot.
Cook over low heat for 30 minutes
After the color comes out in the soup, take the vegetable scraps with a strainer. If you feel the taste is too light, add a little bit of shoyu (soy sauce) and coarse pepper.