Begin by combining 2 tablespoons of kosher salt, finely sliced green onions (reserving the ends for later use), and hot water in a large mixing bowl. Mix thoroughly until well combined. Next, add the cleaned onion ends and chopped cilantro stems to the mixture, stirring until evenly distributed. Gradually incorporate all-purpose flour, stirring with a wooden spoon until the dough starts to form. Slowly add 1 cup of room temperature water while continuing to mix until a soft and pliable dough forms.
Transfer the dough onto a lightly floured surface and knead it for approximately 10 minutes or until it becomes smooth and elastic. Shape the dough into a ball and place it back in the mixing bowl. Cover with plastic wrap and let it rest for 30 minutes to allow the gluten to activate.
After resting, remove the dough from the bowl and roll it out onto a lightly floured surface until it is about 1/8 inch thick. Brush approximately 2 tablespoons of canola oil over the dough, making sure to cover the entire surface. Generously sprinkle a handful of sliced scallions over the oiled dough.
Fold one-third of the dough in towards the center, then fold the remaining third on top, creating a long and narrow strip. Roll this strip back into a ball and let it rest for another 10 minutes. Repeat this process two more times, resting the dough between each fold. This technique creates layers in the pancake, resulting in a flaky and delicious final product.
After resting, roll out the dough once again onto a lightly floured surface, making it slightly thinner than before. Heat a large pan or griddle over medium heat and brush with canola oil.
Carefully transfer the pancake dough onto the pan and cook for approximately 2 minutes on each side, until crispy and golden brown. Repeat with any remaining dough, adding more oil to the pan as needed.
Serve your homemade scallion pancakes warm.