Boil the bullfrog for 30-40 minutes, and the specific steps are as follows:

1. Wash the bullfrog with clear water, remove the head, feet and internal organs, and cut into blocks for later use.

2. Blanch the bullfrog block in boiling water to remove the floating foam on the surface.

3. Add appropriate amount of ginger slices and cooking wine and continue to cook for 10 minute.

4. Add the right amount of salt and soy sauce and cook for about 20 minutes until cooked.

5. Sprinkle with chopped green onion and serve.