Clean pork bones, blanch for 5 minutes, then rinse.

Boil 1.5 liters of water, add blanched bones and 5 shallots, simmer for 30 minutes, regularly skimming off impurities.

Cut tomatoes into wedges.

Finely chop sawtooth herb.

Finely chop the perilla.

Clean and finely chop half of the snail meat (0.55 pounds).

Mix chopped snail meat with 0.22 pounds of pork paste, and season with 1 tbsp fish sauce, 0.5 tsp sugar, 1 tsp minced garlic, and 1 tsp shallot. Add ground pepper for extra spice (optional).

Blanch rice vermicelli in boiling water, then rinse in cold water and drain.

Heat annatto seed oil, sauté 1 tsp minced shallot and 1 tsp garlic. Add remaining snail meat, and season with 1 tbsp fish sauce and 0.5 tbsp sugar.

Sauté 1 tsp shallot and garlic in annatto seed oil, then add tomatoes and cook until tender.

Shape snail patties into small pieces. Fry the snail patties in oil until evenly cooked and golden.

Add sautéed tomatoes and fried tofu to the simmering broth. Season with 1 tbsp salt, 1 tbsp sugar, and simmer for 5 minutes. Finally, add 2 tbsps apple vinegar for a tangy flavor.

Place noodles in a bowl, add snails, snail patties, tofu, and tomatoes. Sprinkle it with coriander and perilla. Pour hot broth over and serve with bean sprouts and shredded water spinach on the side.