Preheat oven to 450 F.
Using two baking sheets, put shredded beets on one, and the zucchini and mushrooms on the other.
Toss vegetables with a olive oil, salt and pepper.
Roast the beets for about 12-15 minutes checking often to make sure they are not burning and carefully tossing with a spatula half-way through.
Roast zucchini and mushrooms for 20 minutes or until golden brown, tossing the vegetables half-way through.
Warm corn tacos by placing on a grill pan or skillet for 2 min per side or until grill marks appear.
Scoop some of the zucchini and mushrooms onto the taco and top with beets, a few cherry tomatoes, dollop of sour cream, squirt of fresh lime juice and some parsley.