What would be a good substitution for sake in a recipe?
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What is the type of recipe? (marinade, cocktail, stir-fry, etc. ?) I would say mirin or maybe vodka but more information will help.
It is to steam kabocha squash with white miso and a touch of sesame oil.
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.