Grilled Tamales with Poblanos and Fresh Corn

Ingredients:
30 dried large corn husks (3 ounces), separated and any damaged husks discarded
1 1/4 pound fresh poblano chiles (about 5)
2 cups corn tortilla flour (masa harina; 9 ounces)
1 cup finely ground cornmeal
1 1/2 teaspoons baking powder
3 cups water
1 cup plus 1 tablespoon lard (1/2 pound), melted and cooled, divided
1 medium white onion, chopped
1 1/2 cups corn (from 3 ears)

Instructions:
Cover husks with hot water in an 8-quart pot or large bowl and soak, keeping submerged with an inverted plate, until softened, about 30 minutes. Rinse husks, 1 at a time, under running water, then pile on a plate. Cover husks with a dampened clean kitchen towel.
While husks soak, roast chiles on their sides on racks of gas burners on medium-high (or on rack of a broiler pan about 2 inches from broiler), turning with tongs, until skins are blackened all over, 4 to 8 minutes. Transfer to a bowl, then cover and let stand 10 minutes.
Peel chiles, then stem, seed, devein, and coarsely chop.
Whisk together tortilla flour, cornmeal, baking powder, and 1 3/4 teaspoons salt. Stir in water and let stand 5 minutes. Add 1 cup lard and stir vigorously with a wooden spoon until absorbed. Let dough stand until ready to use (dough will stiffen).
Cook onion with 1/2 teaspoon salt in remaining tablespoon lard in a large heavy skillet over medium heat, stirring occasionally, until softened, about 6 minutes. Add chiles and corn and cook, stirring occasionally, until corn is tender, 6 to 8 minutes. Remove from heat and cool to room temperature, about 30 minutes, then stir into masa dough.
Put 1 husk on a work surface, pointed end away from you, and, spreading it flat, mound 1/4 cup filling in center, leaving a 1-inch border on both sides. Bring wide end of husk over filling to cover, then fold in sides. Fold pointed end of husk over to form a packet and arrange, folded side down, on surface. Form more tamales in same manner.
Arrange tamales in 2 steamer racks and/or pasta pot inserts, standing them up in 1 layer in rows so they resemble fallen dominoes. Set steamer racks (on top of each other) over boiling water in a pasta pot (use 2 pots if you can't layer your racks; water should not touch racks) and steam, covered tightly, until filling is firm, about 1 hour. (Replenish water as necessary.)
To check for doneness, open 1 tamale to see if filling is firm and separates easily from husk; if it doesn't, steam 5 to 10 minutes more.
Remove steamer racks from heat and let tamales stand 10 to 20 minutes while preparing grill.
If using a charcoal grill, open vents on bottom of grill, then light a large chimney starter full of charcoal (preferably hardwood). When coals are lit, dump them out across bottom rack (do not bank coals). When charcoal turns grayish white (start checking after 15 minutes), grill will be at its hottest. The grill will be at the right heat when you can hold your hand 5 inches above grill rack over coals for 1 to 2 seconds.
If using a gas grill, preheat all burners on high, covered, 10 minutes.
Oil grill rack, then grill tamales, covered only if using a gas grill, turning over once, until grill marks appear on corn husks, 4 to 6 minutes total.