This quick taco filling is perfect for weeknight dinners. Poblano chiles bring rich, earthy flavor but little to no heat. (Every once in a while you can get a hot one, though.) If you want to add a little spice, add some crushed red pepper when you sauté the mushrooms.
Place avocados in a medium bowl; mash until smooth. Stir in chopped cilantro, onion, juice, and 1/4 teaspoon salt; set aside.
Combine crema and adobo in a small bowl, stirring until well blended; set aside.
Heat a large cast-iron skillet over high heat. Add corn to pan; cook 4 minutes or until corn is caramelized and lightly charred, stirring occasionally. Place corn in a large bowl.
Wipe pan clean with paper towels; return to medium-high heat. Add oil to pan; swirl to coat. Add poblano; sauté 4 minutes or until tender. Add mushrooms and garlic; sauté 2 minutes. Stir in remaining 3/4 teaspoon salt; sauté mushroom mixture 4 minutes or until most of liquid evaporates. Add mushroom mixture to corn; stir to combine.
Place 2 warm tortillas on each of 6 plates. Spread 1 1/2 tablespoons avocado mixture in a 4-inch circle in center of each tortilla. Top each with 1/4 cup mushroom mixture, 1 1/2 teaspoons crema mixture, and 1 1/2 teaspoons cheese. Top with cilantro leaves, if desired.