1 teaspoon minced fresh oregano or 1/4 teaspoon dried
Salt and pepper
1-pound sweet potatoes, peeled and cut into 1/2-inch pieces
4 poblano chiles, stemmed, seeded, and cut into 1/2-inch-wide strips
1 large onion, halved and sliced 1/2-inch thick
1 (15-ounce) can black beans, rinsed
1/4 cup chopped fresh cilantro
12( 6-inch) corn tortillas, warmed
PROCEDURE
Adjust oven racks to upper-middle and lower-middle positions and heat oven to 450°F. Whisk oil, garlic, cumin, coriander, oregano, 1 teaspoon salt, and 1/2 teaspoon pepper together in large bowl. Add potatoes, poblanos, and onion to oil mixture and toss to coat.
Spread vegetable mixture in even layer over 2 foil-lined rimmed baking sheets. Roast vegetables until tender and golden brown, about 30 minutes, stirring vegetables and switching and rotating sheets halfway through baking.
Return vegetables to now-empty bowl, add black beans and cilantro, and gently toss to combine. Divide vegetables evenly among warm tortillas and top with optional avocado crema and pickled onions. Serve.