Can i substitute Hondashi or bonito for the anchovy? If so, what would be the equivalent amount of hondashi?

Hi Maria—I'm actually making this recipe for Thanksgiving, too! If the hondashi you have is powdered (not a liquid stock), I would just make the dressing as written, then sprinkle in the hondashi granules to taste (just like you would with salt); if it's a liquid stock, I worry that would thin out the dressing too much. I bet bonito flakes would be delicious, too (both incorporated into the dressing and on top of the salad at the end). Again, I just would add these to taste, until the dressing has the right balance of saltiness and umami to you. Happy Thanksgiving!