Toss the poblano peppers with 2 to 3 teaspoons of canola oil and grill, turning occasionally, until the peppers are nicely charred. (Char scallions and corn on grill at the same time). Immediately place peppers into a bowl and cover with plastic wrap - let sit for 10 minutes to sweat. Peel the skins off then finely chop and combine with the goat cheese, chopped grilled scallions, shucked grilled corn kernels and parmesan. In a large saute pan over grill – add finely diced chorizo and brown for 3-4 minutes unitl oils are released and chorizo is slightly browned. Add to cheese mixture and gently fold together – set aside until ready to use.
Meanwhile, combine salt and masa flour in a large bowl. Pour hot water in, and using a wooden spoon, stir to combine. Add in the melted butter; cover with plastic wrap and let rest for 10 minutes.
Divide the dough into 12 small balls. Place each ball in between 2 pieces of plastic wrap and flatten using a heavy-bottomed skillet, or tortilla press, to about 3 ½” in diameter and 1/4-inch thick.
Heat a cast iron skillet over medium heat. Fry the arepas in 2 teaspoons of canola oil, about 5 minutes per side, until lightly browned - they should have a nice crust on the outside but still be soft inside. Using a sharp knife, cut a pocket into each arepa. Stuff 1 to 2 teaspoons of the charred poblano and chorizo mixture and cheese mixture inside the pocket.