Carefully peel back the corn husks without tearing them off. Remove the silk, then pull off 12 large, intact husks for wrapping. Rinse the husks well and place them in a large bowl. Cover with very hot water to soften while you prepare the filling. Cut the kernels from the cobs; you should have about 5 cups (750 g).

Set aside 1 cup (150 g) of the corn kernels. Put the remaining kernels in a blender with the milk and blend to a coarse, spoonable puree; a little texture is desirable.

Melt the butter in a large skillet over medium heat. Add the onion, bell pepper, and salt. Cook, stirring often, until softened, about 6 to 8 minutes. Stir in the paprika, cumin, and sugar for 30 seconds.

Add the corn puree, reserved kernels, and cornmeal to the skillet. Cook over medium-low heat, stirring constantly, until the mixture is thick enough to mound on a spoon, about 5 to 7 minutes. Taste and adjust the salt. Remove from the heat.

Drain the husks and pat them dry. Lay two husks on top of each other, overlapping them slightly, with the wider ends at the bottom. Spoon about 1/3 cup of the corn mixture in the center and press one cube of cheese into the filling.

Fold the sides of the husks over the filling, then fold up the narrow end to make a secure packet. Tie gently with a thin strip torn from an extra husk, if needed. Repeat with the remaining husks, filling, and cheese.

Pour the water into a large pot fitted with a steamer basket and bring it to a simmer. Arrange the humitas seam-side down in the basket without packing them tightly. Cover and steam until the husks are tender and the filling is hot and set, about 25 to 30 minutes. Add more hot water if the pot starts to run dry.

Let the parcels stand for a few minutes, then serve warm. Diners can unwrap the husks at the table; the husks are a wrapper and are not eaten.