Preheat oven to 325°F.
Toast coriander, cumin and fennel seeds in a small skillet over medium-low heat until fragrant, 2 minutes. Grind in spice mill. Ground spices may be used as well but if you have the seeds toasting them with make them even more nutty and smoky.
Bring pork to room temperature and pat dry; season with kosher salt and pepper. Heat a Dutch oven to medium-high with 2 tablespoons oil, 2 turns of the pan. When oil smokes, add meat and brown well all over. Add beer and reduce a minute, drizzle in honey, cover pot and transfer to oven. Roast 2 1/2-3 hours until very tender. Remove meat to a shallow dish and shred meat with forks. Pour the pan juices over the meat, wipe pot clean and return to stove.
If using fresh tomatillos, char them under a broiler and purée; reserve.
Char peppers and add to food processor with 2 cups chicken stock, purée.
Add a tablespoon of oil to Dutch oven over medium to medium-high heat. Add onions and garlic, ground spices, salt and pepper. Partially cover and cook 7-8 minutes to soften the onions, stirring occasionally. If using flour, sprinkle over the onions and stir a minute to cook it out. Add tomatillo and chili purées, remaining 2 cups of stock and frozen corn; stir in masa harina at this point, if using. Add pork and pan juices, fresh tomatoes and season with salt to taste. Simmer to thicken to your liking.
Serve chili with wedges of lime and toppings of your choice.