Slice the chicken into 1-inch pieces. Skinless chicken thighs can also be used in this recipe.
In a large pot, heat the vegetable oil over medium high heat.
Place chicken pieces skin-side down in the hot pot and cook for about 3 minutes until the skin is crispy and golden brown. Flip the chicken and cook for another 3-5 minutes to brown the other side. Note: brown chicken in a single layer in the pot. If necessary, brown chicken in multiple batches.
Pour in the dashi, shoyu, mirin, sugar, sake (if using). Stir to combine ingredients together.
Bring to a boil and reduce to a simmer. Continue to cook and skim the surface for impurities for 15 minutes.
Add the frozen Wafu Yasai Mix, konnyaku, sliced into ½ inch pieces (if using), aburaage, sliced into strips, and kombu to the same pot. Rehydrate the kombu in water then cut into 2 inch pieces or tie them into knots.
Cook for another 15 minutes and adjust seasoning with extra shoyu or dashi as needed.
Add in the sliced green onions. Serve with hot rice.