Scientific method to microwave octopus I want to cook about 300 g of parboiled frozen octopus.  I am sorry to say that the parboiled octopus is white, not translucent but good quality, freshly produced.

The octopus therefore needs to be boiled to soften.

If I have a microwave, can I put the 300 g octopus in a glass dish and cook it for two to three hours in a microwave to soften?

Any recipes and formulas to convert the microwave output to percentage setting and time will be appreciated.
If you want to boil something in your microwave, you certainly can. I doubt it'll be as power-efficient as doing it on the stove, but it's possible.

But there's no formula to get you a time and power level. You probably want to heat on maximum power until the water boils, then heat on the lowest power setting which keeps the water boiling until the octopus is done how you want.

On top of that, depending on your microwave, even the lowest power setting may be too high, and cause water to boil away enough that you'll need to replenish it eventually if you're cooking for an extended period.