Meat and Vegetables: Heat the oil in a medium saucepan on high heat. Note: olive oil has a much lower smoke point than other oils. Not recomended. Note: if using cooked meat, skip to step 2. Add meat if raw. Cook and stir for about 5 min or until mostly done.

Note: If you want to reduce the heat, wait to add thai pepper or red pepper flakes until step 7. Add mushroom, carrot, cabbage, and Thai pepper or red pepper flakes. Cook for another 5 min or until carrots are softened slightly.

If using cooked meat, add now. Add 1 tablespoon of soy sauce. Stir until the mixture is coated with the soy sauce.

Add chicken broth or stock.

Note: Read this step completely before doing it. Add remaining soy sauce and vinegar, one tbs at a time, alternating between soy sauce and vinegar. Taste after each tablespoon addition to ensure that the flavor is to your liking. It should have a balanced flavor between salty and sour (you should be able to taste both equally). Adjust as necessary by adding more or less soy sauce or vinegar.

Combine cornstarch and water in a separate bowl or cup.

Add tofu and cornstarch/water mixture. If you haven't aready, add the Thai pepper or red pepper flakes now for less heat.

Bring to a full boil. The broth will thicken slightly.

Critical step: After it reaches a boil, remove from heat for about 30 seconds. While stirring slowly, slowly drizzle the beaten eggs into the soup. Note: if the broth is too hot, the eggs will overcook and disintegrate, making a milky broth instead of long ribbons like it's supposed to. Don't worry, it still makes a tasty soup, although the presentation won't be as great.

Keep the heat off, but finish the soup by adding the sesame oil and white pepper. Stir to blend.

Provide sliced green onion for garnish. Serve.