Prep the corn husks: Add the corn husks to a large bowl or pot. Pour enough hot water over the corn husks to cover them completely. Cover the bowl with aluminum foil and let them soak for 1 hour to soften them up.
Roast the chiles: Spray a large baking sheet with nonstick cooking spray or grease with oil. Place the tomatillos, jalapenos, poblanos and serrano peppers on the baking sheet and place under broiler. Broil on high for 10 minutes, turning the tomatillos and peppers over halfway through.
Remove the skin: Remove the baking sheet from the broiler and cover with aluminum foil or plastic wrap. Let it sit for 10 minutes. Uncover and remove as much of the skin from the peppers and tomatillos as you can. At this point, you can also remove the seeds from any of the peppers if you don't want it too spicy.
Make the green chile sauce: Add the roasted tomatillos, all the peppers, onions, garlic, salt and water to a large blender. Blend until smooth. Set aside until ready to use.
Cook the chicken: Heat oil in a Dutch oven or large pot over medium-high heat. Add chicken, season with salt and cook for 15 minutes, stirring occasionally, until chicken is no longer pink.
Simmer the chicken: Add green chile sauce and bring to a boil. Once boiling, reduce to a simmer and cook uncovered for 15 more minutes. Taste and season with more salt if necessary. The chicken should be tender and cooked through. If it's still a little tough, cook for another 15 minutes. Remove from heat and mix in the lime juice. Set aside.
Mix the masa harina: In a very large mixing bowl or pot, add masa harina, salt and baking powder. Combine and mix with your hands.
Add the oil: Add canola oil and mix together, working the dough through your fingers until everything is well combined and incorporated. The dough should feel a little crumbly, almost like wet sand, and should lightly hold it's shape when pressed together.
Add the broth: Add broth and mix for about 3-5 minutes until the dough is fairly wet and well saturated. The dough should be soft and spreadable like thick hummus. If the dough is too dry, add more broth. If it's too wet, add more masa harina.
Finish prepping the corn husks: Drain the water from the corn husks and pat them dry. Lay them flat onto a baking sheet for easy access.
Spread the masa onto corn husks: Grab a corn husk and identify which is the smooth side and which is the side with ridges. Place the smooth side face up into your palm or on a plate. Using a large spoon, grab a heaping spoonful of masa and place it in the middle of the corn husk. Using the back of the spoon, spread the masa in a thin layer to create a rectangle shape, leaving the top 1/3 of the corn husk empty. (see post above for step-by-step photos)
Add the filling: Using a different spoon, place about one tablespoon or so of the green chile chicken into the center of the corn husk. Don't put too much filling or it will overflow when you close it.
Fold: Fold together the long edges of the corn husk like a book, and then fold it once more. Fold the pointy edge over so that only one side of the corn husk is open and exposed, and secure the folded edge with thin strip of corn husk by tied a knot around the tamale. If you don't want to go to the trouble of tying a knot around each tamale, you don't have to.
Prepare the steamer pot: Fill the bottom of the steamer pot with water and cover with the steamer insert. Place the tamales in the steamer with the open end facing up, making sure to lean them against the side of the pot so they don't fall down.
Steam: Cover tightly with the lid and place steamer over medium-high heat. Cook for 3 1/2 hours, or until the masa is fully cooked. To check and see if it's cooked, carefully remove a tamale and open it up. The masa should easily separate from the corn husks and it should be fairly firm. When ready to eat, remove tamales from steamer, let sit for 3 minutes to cool, then serve.