1, both will do. Boiling purple potato in water is the most sufficient for the nutritional retention of purple potato, which can retain as much sweetness as possible, and the steamed taste will be softer and glutinous, while boiling purple potato in water will be relatively moist and not so dry. Generally, you can decide the cooking method according to your own needs and preferences.

2. If the purple potato is boiled directly in water, it is more hygienic to clean the dust and dirt on the surface of the purple potato before cooking.

3. Purple sweet potatoes generally don't need to be steamed for too long. Generally 15-20 minutes can be steamed.

4. To judge whether the purple potato is ripe, you can poke it with chopsticks. If you can poke it easily, it means that the purple potato is ripe.