I changed/substituted quite a few things. I left out the currants completely (since many said the dish was too sweet), added some salt, and made the following substitutions:
-sweet potato for squash
-spinach/arugula blend for spinach
-cilantro (added at the same time as the spinach) for sage
-chicken broth for veggie broth
-hot sauce for balsamic reduction
The hubby and I LOVE this dish with our changes. The arugula helped with the sweetness issue and the hot sauce really finished the dish off nicely. We will definitely make this again.