1. Soak raw ribs in water for half an hour, and then wash them.
2. While soaking ribs, prepare auxiliary materials.
3. Add a proper amount of water to the pressure cooker, add ribs, seasoning boxes, onion and ginger, boil over high fire, simmer for 20 minutes on low fire, and turn off the fire.
4. While stewing the ribs, peel and cut the yam and soak it in white vinegar to prevent oxidation and discoloration. Wash anoectochilus roxburghii with clear water for later use.
5. deflate and open the lid, and put the yam into the pot;
6. Put the anoectochilus roxburghii in the pot and stew for 20 minutes with the lid half open.
7. Add salt to taste before turning off the fire, and add a few medlar to turn off the fire.
8. Cooked anoectochilus roxburghii can be eaten directly.