Heat the butter in a medium-size skillet over medium heat. Add the onion and cook, stirring, until soft and lightly golden, about 5 minutes. Heat the milk in a saucepan. Add the bay leaf, thyme, marjoram, and the peppercorns. Just before the milk comes to a boil, add the onions, remove from the heat and cover.
In a food processor, puree the chilies, tomatillos and 2 boxes of the corn.
Add the pureed mixture and the remaining box of corn to the milk mixture. Simmer over very low heat for 30 minutes. Add salt to taste.
Pour the soup into individual bowls over cubes of cheddar. Garnish with the cilantro. Serve with warm crusty bread.
Make 4 to 6 servings