Pig Tail Soup -Canh Duoi Heo

2 lb pig tail (They are sold in package at Winco)
3 medium carrot, peel and cut into bite size of your choice
4 medium potatoes, peel, cut into bite size
3 celery ribs, cut into bite size, remove tough outer fiber if seeing them during cutting
1 yellow onion, cut into 8pieces
2 garlic cloves, crushed
2 bay leaves
1 green onion, thinly sliced
2 tsp salt for seasoning and  1 Tbs salt  for cleaning tails
2 Tbs fish sauce and 1 Tbs fish sauce  for dipping
1 tsp sugar
1/4 tsp ground black pepper
1 hot pepper, thinly sliced
1 small piece of lime or lemon

1. Cut pig tails into 1.5-in chunks, wash with water a few times, drain. Then sprinkle salt over pig tails (about 1 Tbs salt), give them a good massage, then rinse with water.  Put them in a 6-quart pot, cover with water, bring it to a boil for 5 minutes over medium high  or high heat.  Drain, and rinse well with water. Wash the pot, add 2 quarts water, bring it to a boil, add pig tail, onion, garlic, carrot, and celery, pepper and salt. Bring it back to a boil then simmer over medium low heat about 30 minutes.
2. Add potato, add sugar, fish sauce.  Cook for 15 more minutes, check and make sure pig tails and vegetable are tender. The pig skin will taste better if it soft but still has some bite like crunchy texture.
3. Taste and adjust seasoning as needed, add green onion.  
4. Ladling soup into serving bowl, sprinkle with ground pepper if you like serve warm with cooked rice or by itself. 
5. Dipping sauce for pig tails:  In a small bowl, add 1 Tbs fish sauce, a few slice of hot pepper, and lemon or lime juice.
6. When it is cool or cold, gelatin from bone and skin might make the broth has a jello texture. It is ok to eat cold or reheat.