Place broth, onion, gingerroot and mushrooms in pot; bring to boil and simmer for 5 minutes or until vegetables are tender-crisp. Add tofu and cook for 1 minute. Stir in fish sauce, lime juice and chili sauce; simmer for 5 minutes. Add shrimp and bring to boil. Slowly stir in beaten eggs with fork. When eggs form threads, remove from heat and add coriander.
Chinese Hot and Sour Soup: Use white vinegar instead of lime juice and soy sauce instead of fish sauce. After eggs are cooked, add 1 tsp (5 mL) sesame oil and 2 chopped green onions.
Fish sauce is the Thai version of soy sauce. It does not colour the soup like soy sauce, and after cooking it has a mild taste. If unavailable, use soy sauce.
Substitute diced chicken breasts or pork tenderloin for the shrimp but add them along with the tofu to allow enough cooking time. Or, if you wish, add precooked meat or vegetables to the soup just before the eggs.