Preheat oven to 425 degrees. On a large rimmed baking sheet, toss mushrooms with 1 teaspoon oregano, 1 tablespoon oil, and 1/4 cup water; season with salt and pepper. On another rimmed baking sheet, toss zucchini and onion with remaining teaspoon oregano and tablespoon oil; season with salt and pepper.
Place both sheets in oven. Roast, tossing occasionally, until vegetables are browned and fork-tender, 25 to 30 minutes (zucchini may cook faster than mushrooms).
Meanwhile, in a small skillet over medium-high heat, warm tortillas according to package instructions (they should be lightly browned but still soft). Wrap loosely in a clean kitchen towel to keep warm.
To serve, fill each tortilla with mushrooms, vegetable mixture, shredded cheese, and salsa.
To clean portobellos, snap off stem, then use a small spoon to gently scrape (then discard) the dark gills from the inside of the cap.
This was a quick and easy meal - and tasty too! I didn't have oregano so I used basil. I will def make this again.
Super easy, great tasting, and will serve to others......good posting for us vegetarians. I think that there should be a vergetarian week of recipies for the show because it is so hard to find stuff that is quick and easy to make as well as taste great.
We have been making these for years, they're always a hit. They are the first thing I think of serving if I know I have vegetarians coming to dinner. None of my other guests ever miss having meat when portobellos are used. The flavors are great together, and I absolutely prefer these to "regular" tacos.
As a vegitarian, I think this is GREAT recipe, but I have to disagree on the price of portabellas. Boneless/Skinless chicken breasts are at least $2/lb cheaper here on the west coast. I use portabellas almost on a daily basis and I've yet to see them below $4.99/lb.
That said, grilling (on the BBQ) the mushrooms and veggies adds a whole new dimention to their flavor. Same goes for the tortillas. After all, who wants to turn on the oven when it's 100 degrees outside?