6 portobello mushroom caps (about 1 lb., 2 oz.), gills removed
3 tablespoons grapeseed oil
1 1/2 teaspoons ground cumin
1 1/2 teaspoons ancho chile powder
1 small yellow onion, thinly sliced (about 1 cup)
1 small red bell pepper, seeded and thinly sliced (about 1 cup)
1 small yellow bell pepper, seeded and thinly sliced (about 1 cup)
1 medium poblano chile, thinly sliced (about 1 cup)
1 teaspoon kosher salt
8 6-in. corn tortillas
8 lime wedges, for serving
Mexican hot sauce, for serving, optional
1. Heat a grill pan over high heat. Brush portobellos with 1 1/2 tablespoons of the oil. Stir together cumin and chile powder in a small bowl. Sprinkle half of cumin mixture over portobellos, pressing to adhere. Grill portobellos until lightly charred and tender, 5 to 6 minutes per side. Remove from heat.
2. Heat remaining 1 1/2 tablespoons oil in a large skillet over high heat. Add onion, bell peppers, and poblano; sprinkle with remaining cumin mixture and 1/2 teaspoon of the salt. Cook, stirring often, until lightly charred and tender, 4 to 6 minutes. 3. Heat tortillas according to package directions. Thinly slice portobellos; sprinkle with remaining 1/2 teaspoon salt. Divide portobellos evenly among tortillas. Top evenly with onion mixture. Serve with lime wedges and hot sauce, if desired.