Once at a restaurant and I had the inside of a sweet onion baked whole until blackened with just dengaku miso. The onion's sweetness was so great that I wanted to recreate this dish without baking, so I tried steaming.

Steam the sweet onions until a skewer can easily pierce through.
But using a microwave is okay. I just somehow thought that steaming will keep the flavor from escaping.
It's also plenty good without cheese and just the dengaku miso. Recipe by Miyacchu