01 -
Preheat the oven to 350°F (175°C) and lightly grease a 1 1/2-quart casserole dish.
02 -
Bring a large pot of lightly salted water to a boil. Cook the egg noodles for about 5 minutes, until almost tender. Drain well.
03 -
Heat olive oil in a heavy skillet over medium heat. Add the chopped onion and cook for 4 to 5 minutes, stirring frequently. Stir in the cooked chicken, red bell pepper, celery, and chicken stock. Bring to a boil and simmer for 5 minutes. Mix in the sour cream and oregano.
04 -
Spread half of the chicken mixture into the prepared casserole dish. Arrange asparagus pieces on top. Spread the cooked noodles evenly over the asparagus, and sprinkle with 5 tablespoons of Parmesan cheese. Cover with the remaining chicken mixture, and sprinkle the remaining 3 tablespoons of Parmesan cheese on top.
05 -
Bake the assembled dish in the preheated oven for about 30 minutes, or until the cheese has melted and the top is golden brown.