Heat oil in a saucepan, and fry all of the chopped vegetables and pork except for the tofu. When everything is well-coated in oil, pour in the water for the dashi stock and bring to a boil. Cook over high heat, skim the scum from the surface, and turn down the heat to low.
Once the vegetables have softened, add the soy sauce and dashi stock granules, and taste to adjust. Continue simmering over low heat.