• Separate tamal leaves and place them in a large pot. I generally use my tamalera, or a large pot without the rack. Cover with warm water and let them hydrate for at least an hour.
• Tip: The leaves tend to float, so keep them submerged by placing another smaller pot with water in it on top of them.

Prepare the Filling

• In a blender, blend the tomatillos, onion, serrano chiles, water, cilantro, oregano, and a tablespoon of salt.
• In a medium-size pot, heat a tablespoon of olive oil. Add the green salsa and simmer for 5-7 minutes until the salsa turns olive green in color.
• Add the chicken, stir well to combine with the salsa and heat for 5 minutes. Set apart.

Prepare the Masa

• Add the masa flour to a large bowl, add the salt, olive oil, melted butter, and 4 cups chicken broth.
• Leave it be, don't touch it or stir it, let it stand for 10 minutes. Little by little the liquid will hydrate the masa, by doing this you will be saving time and effort when it comes time to use it.
• While you wait, drain and dry the tamal leaves with a kitchen towel. Set apart.
• Now stir the masa until the masa has absorbed all the liquid, the consistency looks a little dry, at this point begin adding chicken broth a half cup at a time, until you get a moist and smooth consistency so that it spreads easily.
• In most cases, you will use about 6 cups, but it's best to add the broth little by little in case climatic conditions make the masa moist enough with less liquid.
• Cover the masa with a moist cloth kitchen towel to keep it from drying out.

Assembling the Tamales

• Prepare your work area. You'll need enough space to have the filling, the masa and the leaves within reach.
• Take two or three tamal leaves (choose the smallest) and with your fingers separate them to form thin strips to use as ties for the tamales. Set apart. (See 3 photos below)
• Place one tamal leaf down in front of yourself and take a small ball of the masa about 2 inches (4cm) in diameter.
• With your hands, press it into the shape of a thick tortilla. Place about two teaspoons of filling in the center.
• Now close up the masa around the filling and place the small ball in the middle of the leaf at the widest part. Wrap it up and and fold it so both ends are facing up.
• Take one of the leaf strips you made to tie the two ends of the leaf together.
• Repeat until you've used all of your masa and filling.
• Next, add water to the bottom of your steaming pot and place the rack inside, making sure the water level stays below the rack. If you have extra husks, put half of them over the rack to protect the tamales from direct contact with the water.
• Place the tamales inside the steamer, top with remaining leaves, cover with the lid. Place over high heat until the water begins to boil.
• Lower the temperature to medium-low, the important thing is that it continues to steam without steaming off all of the water from the bottom.
• Continue to steam the tamales for about an hour or until they are cooked. You will know they are done when they separate from the leaves easily when you carefully open them up.
• Something important to keep in mind. The steam will make the tamales feel a little wet and loose. This is normal. If the tamal comes off the leaf easily, they are done, even if they look a little wet still.
• As they cool, they will get firmer.