Cook the bacon in 2 teaspoons of the oil in a heavy pot or Dutch oven over medium heat until crisp. Remove and set aside, reserving the bacon fat in the pot.
Use dry hands to pull off the skin from the chicken thighs and discard. Trim any large pieces of fat. Sprinkle the chicken legs and thighs with salt and pepper and brown over medium-high heat in the Dutch oven. Remove the chicken and set aside. Lower the heat to medium and cook the carrots, celery and onions in the remaining oil over medium heat until tender and fragrant. Sprinkle with flour and cook 1 minute, stirring. Deglaze the pan with the chicken stock. Add back the chicken and the bacon, and pour enough water to almost cover the chicken, 1 to 2 cups. Cook, covered, over low heat for 30 minutes and then uncovered for 15 minutes. If the sauce is not thick enough, let it reduce longer. Serve over the Sour Cream Garlic Biscuits.
Chill the butter in the freezer while gathering the other ingredients. Preheat the oven to 425 degrees F.
Place the flour, baking powder, baking soda, oregano, salt and garlic in a food processor and pulse. Add the butter and process until the mixture resembles wet sand. Add 1/2 cup sour cream and pulse until a dough is formed. Place the dough on a floured surface and form into a thick disc, about 4 inches in diameter. Cut into 6 wedges. Brush the tops with the remaining sour cream. Bake until fluffy and golden, 11 to 15 minutes.