For the Cheddar and Green Onion Biscuits: Preheat the oven to 475°F.
1 1/4 cups self-rising flour
3/4 cup cake flour
3/4 teaspoon baking powder
1/8 teaspoon baking soda
1 tablespoon sugar
1/2 teaspoon salt
Sift the self-rising flour, cake flour, baking powder, baking soda, sugar, and salt together into a large bowl.
4 tablespoons (1/2 stick) cold unsalted butter (cut into pieces)
1/3 cup grated cheddar cheese
2 tablespoons chopped green onion tops
1 1/2 cups heavy cream
Using your fingers or a pastry cutter, work the cold butter into the flour until the pieces are pea size. Add the cheddar and green onions. Pour the heavy cream into the mixture, and with your hands or a rubber spatula, stir just until the cream and flour come together to form a dough.
1/4 cup all purpose flour (for dusting)
Sprinkle some of the all-purpose flour on a work surface and place the dough on top of the flour. Using a lightly floured rolling pin or your hands, shape the dough into a 1/2-inch-thick disk about 8 inches in diameter. Using a sharp 3-inch round cutter dusted with flour, cut out 6 dough rounds. Be sure to press straight down when cutting the dough—a twisting motion will prevent the dough from rising.
3 tablespoons melted butter
Place the biscuits on an ungreased baking sheet and brush the tops with the melted butter. Bake until golden brown, 10 to 12 minutes.
1 1/2 pounds boneless and skinless chicken thighs (trimmed of excess fat)
For the Chicken: Place the chicken between two pieces of plastic wrap and use a mallet or the bottom of a heavy skillet to pound each piece to a thickness of about ¼ inch.
1 cup evaporated milk
1 tablespoon freshly ground black pepper
2 teaspoons minced garlic
In a medium bowl, mix the evaporated milk, 1 tablespoon of the pepper, and the garlic. Add the chicken pieces, cover, and refrigerate for 4 hours or up to overnight.
2 cups all-purpose flour
2 teaspoon salt
In another medium bowl, combine the 2 cups flour with 2 teaspoons of the salt and 2 teaspoons of the black pepper. Remove the chicken from the marinade (reserve the marinade). Lightly dredge the chicken pieces in the flour, shaking to remove the excess, dip them in the marinade, and then dredge them in the flour again. Set the chicken aside on a cooling rack or plate.
4. Fill a cast-iron skillet or other heavy-bottomed pot with vegetable oil to a depth of 1 inch, and heat it over medium-high heat to 350°F. Add a few pieces of the chicken to the pan and cook until browned on one side, about 3 minutes. While the chicken is cooking, continue to monitor the heat of the oil with a deep-frying thermometer, making sure the temperature stays between 330° and 350°F. Turn the chicken and cook on the other side for 3 to 4 minutes, until golden and cooked through. Remove the chicken from the pan and set it aside on a paper-towel-lined plate to drain. Repeat with the remaining chicken pieces.
Vegetable oil (for frying)
Remove all but 2 tablespoons oil from the skillet, and add the onion. Cook over medium heat, stirring as needed and scraping up any browned bits in the pan, until the onion is soft and translucent, about 5 minutes. Add the remaining 2 tablespoons flour, stir well to combine, and cook for 2 minutes longer to make a roux. Whisk in the coffee and chicken stock, and cook until the sauce has thickened, about 6 minutes. Add the heavy cream, green onion, remaining 1 teaspoon pepper, and remaining 1/2 teaspoon salt, and cook for 2 to 3 minutes more, until the gravy reaches the desired consistency. If the sauce thickens too much, thin it with additional chicken stock.
6. To assemble: Slice a biscuit in half. Set a piece of fried chicken on the bottom half, spoon some of the gravy over the chicken, and top with the other half of the biscuit. Repeat with the remaining chicken, biscuits, and gravy. Serve immediately.