Tofu doesn't works for burgers, at least that's my opinion. And veggies makes them taste like salad sometimes. What I tend to do is to peel, cut, and cook, some eggplants, blend them, and mix that with wheat, give them burger shape, and that's it, they really taste good. Try them and let me know.I'm not sure if I like tofu. But I'm okay with vegetables. Sometimes burgers taste like salad because of the recipe. I actually prefer them compared to the usual greasy taste.