By default, you can use it only with the products whitelisted in the manual (a very limited selection, if you ask me). Trying hard to cut items (raw coconuts or pumpkins) may damage the rotor schaft, or malform the knife disc.
Boiling, baking or steam-cooking makes the vegetables softer. Here's what I tried so far:
- Mushrooms. If they're too soft, it won't be able to produce cubes, but it will still cut them
- Onions
- Slightly baked pumpkin