Preheat the oven to 300°F.
Spread corn on one or two baking sheets and cook until toasted, about 30 minutes. Let cool.
Place cooled corn in a food processor or blender (I use my powerful VitaMix because it can be easily controlled and the result is just right). Do not over-process so that it becomes like flour, it should be a somewhat coarse flour with a few bits of corn the size of half a rice kernel.
Cover processed corn with cold water and let soak about 30 or 40 minutes. The larger pieces will float; remove and reserve them until the rest of the ingredients are ready.
Place the rest of the corn flour in a cooking pot and add 2 quarts of chicken stock.
Meanwhile, remove the tops of the chiles and shake out the seeds. Cut a slit down one side and open them carefully so that they can lie flat. Remove the veins if desired.
Heat a griddle or comal over medium heat and toast the chiles on both sides, taking care not to burn them.
Place in a bowl, cover with boiling water and let soak for 20 minutes. Transfer to a blender and add a cup of stock or water and process until smooth.
Pass through a medium sieve into the pot with the corn. Add the reserved corn bits and any water that accumulates. Add hoja santa and salt to taste.
Bring to a boil over high heat, and then lower heat to maintain a simmer. Cook until thickened to the consistency of heavy cream or a little more. Taste and adjust seasoning. (The corn tends to absorb a lot of the salt.)
Serve with cooked chicken or pork