Roast the poblano: Preheat the broiler, and line a baking sheet with foil. Put the poblano, skin-side up, on the prepared baking sheet and broil until the skin is wrinkled and charred in spots, 2 to 3 minutes. Transfer the poblano to a small bowl, cover with plastic wrap and let steam for 5 minutes. Run the poblano under cold water, and remove and discard the skin. Cut the poblano into very small pieces and return them to the bowl.
Make the filling: Toss the chicken with 1 teaspoon oil, the chili powder and 3/4 teaspoon salt in a medium bowl. Transfer to the baking sheet and broil until browned in spots and cooked through, 4 to 5 minutes per side. Let cool for a few minutes, cut into chunks, then transfer to a food processor. Add 1 cup of the cheese, half the scallions and 1/4 teaspoon salt, and pulse until the mixture is coarse and holds together when squeezed.
Make the cheese sauce: Melt the butter in a small saucepan over medium heat. Add the flour and stir until the mixture is light brown, about 45 seconds. Whisk in the milk, and continue whisking until the mixture begins to bubble and thicken, about 4 minutes. Stir in the remaining 1 cup cheese, the chopped poblanos, hot sauce, garlic and 3/4 teaspoon salt. Set aside and keep warm.
Roll the taquitos: Wrap the tortillas in a damp cloth and microwave for 1 minute so they are warm and pliable. Lay the tortillas out, and spread 1/4 cup of the filling down the middle of each. Roll each up, and secure with a toothpick. Push the filling into the sides a little so that it doesn't fall out. Fry the taquitos: Heat about 1/4 inch of oil in a large skillet over medium heat. Once the oil is shimmering and hot, add half the taquitos, and fry until golden brown on all sides, about 4 minutes, turning as needed. Remove to a paper towel-lined plate, and sprinkle with salt. Repeat with the remaining taquitos.
To serve: Remove the toothpicks and arrange the taquitos on a serving platter. Drizzle with some of the cheese sauce, and top with the remaining scallions. Serve the remaining sauce on the side, for dipping.
Sponsor recipe courtesy of Sargento®