Sake substitution

Yum, white miso and sesame oil! I think mirin would work well if you have it and if you don't I think the sake could be skipped altogether. Maybe the tiniest pinch of white sugar would replace that trace of sugars but not necessary.

It is to steam kabocha squash with white miso and a touch of sesame oil.

What is the type of recipe? (marinade, cocktail, stir-fry, etc. ?) I would say mirin or maybe vodka but more information will help.