Because this is such a substantial guacamole, chef Rick Bayless likes to serve it less as a dip for chips and more as an accompaniment to smoky, grilled shrimp, chicken, fish or pork. (You’ve already got the grill hot, so might as well use it as much as possible.) This recipe comes from Negra Modelo.
If you don’t have epazote, don’t worry. Cilantro is good here, too, though you may want to add an extra tablespoon.
Heat a gas grill to medium or light a charcoal fire and let it burn until medium hot and the coals are covered with gray ash.
Lightly brush both sides of the onion slices with oil, sprinkle with salt, and lay on the grill. Oil the corn and lay it beside the onion along with the poblano (no oil needed). When the onion slices are browned on one side, 4 or 5 minutes, flip them and grill the other side. Turn the corn regularly until evenly browned, about 5 minutes. Roast the poblano on the hottest part of the grill for 5 to 7 minutes, turning it until evenly blackened.
Let the roasted vegetables cool. Chop the onion into ¼-inch pieces. Cut the kernels from the corn (you need about ¾ cup). Rub the blackened skin off the poblano, pull out and discard the stem and seed pod, tear open the flesh, and briefly rinse to remove stray seeds and bits of blackened skin; cut into ¼-inch pieces.
Cut the avocados in half, running a knife around the pit from top to bottom and back up again. Twist the halves in opposite directions to release the pit from one side. Scoop out the pit, then scoop the flesh from 1 avocado into a large bowl. Scoop the flesh from the other two avocados onto a cutting board and cut into ½-inch pieces. With an old-fashioned potato masher, large fork, or the back of a large spoon, thoroughly mash the avocado that’s in the bowl.
Scoop the diced avocado into the bowl along with the grilled onion, corn, poblano, and 2 tablespoons of the fresh cheese. Sprinkle with the lime and epazote, then gently stir the mixture to distribute everything evenly.
Taste and season with salt, usually about 1 teaspoon. Cover with plastic wrap directly on the surface of the guacamole and refrigerate. When you’re ready to serve, scoop it into a serving bowl and sprinkle with the remaining cheese.