All you need to do is cut, microwave, mash and mix the vegetables!! It will be ready in 15 minutes. You can substitute the sweet potato with a kabocha squash.
I often make soup so my daughter would eat vegetables. It's quick and easy, but very nutritious.
It's also delicious to use a kabocha squash instead of the sweet potato. Microwaving the vegetables in the silicone steamer reduces the cooking time. If you want to make it creamy, add more milk.
Enjoy Japanese food around the world.