Funny thing about mushrooms:  although they’re about 80% water to begin with, they have the spongelike ability to soak up a bunch more liquid besides.  In this meatless recipe, the mushrooms start by absorbing a very flavorful lime-and-cumin marinade.  Then they’re charred under the broiler along with tomatoes, onion, and garlic.
They’re rolled in warm tortillas and topped with sour cream and avocado. The sour cream and avocado are a cooling complement to the spicy filling.  If you’d like, you can swap in yogurt for the sour cream and basil for the cilantro.

1 1/2 pounds Portobello mushrooms (about 6 medium to large)
3 tablespoons fresh lime juice
2 teaspoons ground cumin
Kosher salt
1/4 cup plus 1 tablespoon vegetable oil
3 cloves garlic, 2 unpeeled
3/4 pound plum tomatoes (about 3 medium)
1 medium unpeeled onion
Freshly ground black pepper
Eight 8-inch flour tortillas
Half of a 4 1/2-ounce can chopped green chiles
1 ripe Hass avocado
1/2 cup fresh cilantro leaves
3/4 cup sour cream

Place an oven rack 4 inches from the broiler heat source and preheat the broiler (see Note). Clean the mushrooms; remove and discard the stems (or reserve them for another use such as vegetable stock); scrape out the gills with a spoon and discard them. Slice the caps in half and then slice crosswise into 1/2 inch thick strips (about 8 cups).

Whisk together the lime juice, cumin, and 1/4 teaspoon salt in a medium bowl until the salt has dissolved; whisk in 1/4 cup vegetable oil. Press in the peeled garlic clove (about 1 teaspoon) and whisk again. Transfer to a resealable plastic bag, add the mushroom slices and knead gently to make sure the marinade is well distributed. Set aside the mushrooms to marinate while you prepare the tomatoes and onions.

Core the tomatoes; slice the onion 1-inch thick. Arrange the tomatoes, onion, and the remaining 2 unpeeled garlic cloves in one layer on a rimmed baking sheet; drizzle them with 1 tablespoon vegetable oil and sprinkle them with salt and pepper to taste.  Broil them, turning them frequently, until the garlic is tender, about 10 minutes. Transfer the garlic to a bowl and continue to broil the tomatoes and onion, turning them frequently, until the tomatoes are tender and the onion is charred at the edges, 8 to 10 minutes more.

Meanwhile, wrap the tortillas in aluminum foil and warm them in the oven as far away as possible from the broiler (if your broiler is in the top of the oven, use the lowest rack of the oven under the broiler pan; if it is under the oven, use the highest rack). Drain the chiles. Halve, seed, peel, and medium chop the avocado (about 1 cup). Finely chop the cilantro (about 1/4 cup).
When the tomatoes and onion have cooked, transfer them to the bowl with the garlic to cool slightly. Place the mushroom slices on the baking sheet and broil them, turning them frequently, until they are tender, 8 to 10 minutes. Transfer them to a medium saucepan when they are done.

Remove and discard the skins from the tomatoes, onion, and garlic. Transfer the vegetables to the bowl of a food processor fitted with the chopping blade; pulse until they are medium chopped. Add the mixture to the mushrooms along with the chiles (about 3 tablespoons) and salt and pepper to taste and stir well. Cook over medium heat until hot.

Spoon some of the mushroom mixture onto each of the 8 tortillas and roll up the tortillas.  Transfer 2 tortillas to each of 4 dinner plates and top each tortilla with some of the sour cream, chopped avocado sprinkled with salt, and cilantro.

Note: If the heating element in your broiler does not cover enough space to cook the vegetables evenly, preheat the oven to 500°F and follow the same timing instructions.

Yields 4 servings
Hands-on time: 25 minutes
Total preparation time: 40 minutes