Why I didn't think of this earlier in the summer, when the zucchini beast was putting out two zukes a day, I don't know. But here it is, a veggie taco that combines the best of summer produce...

If there's anything that comes close to a Mexican version of an open-faced sandwich, the tostada is it. Just when you thought nothing could get messier than taco night, along comes the tostada, wh...