Vegan Baked Vegetable Medley with Yakitori Sauce

3 Japanese eggplants, sliced

2 green bell peppers, chopped into 1" squares

2 russet potatoes, peeled and sliced

1/2 of a small kabocha squash, chopped into 1" squares

2 packages broiled tofu, chopped into 1" squares

24oz baby portabello mushrooms (2 packages)

2 bottles yakitori sauce