In large pot over med-high heat, add oil, and saute all veggies till mushrooms are tender. Add stock, vinegar, soy sauce, and chili puree. Bring to a rapid boil.
Add chicken and tofu; reduce heat to simmer for 15-20 minutes while adjusting seasonings to taste. Stir occasionally.
In a small bowl, blend cornstarch and enough water to make fluid-add to soup, stir till slightly thickened. Whisk eggs in bowl and slowly pour in thin stream into soup while stirring constantly- they will cook immediately!
For those who like it very hot, offer a few drops of pepper oil to each serving.