In a large stock pot over medium heat, melt 3 tablespoons butter.
Add in the diced celery, carrots, onions, and garlic. Then season with salt, pepper, oregano, and basil. Stir regularly, sautéing until the vegetables are tender, about 5 to 7 minutes.
Stir in 1/3 cup of all purpose flour, allowing it to fully coat the vegetables.
Very slowly stir in the chicken stock. Start with just a little at a time, about two tablespoons, only adding more once the last bit is absorbed. It should take at least a minute to stir in all of the stock.
Once all of the stock is added, bring it to a boil. Then add in the chicken (cutting very big breasts in half to reduce their thickeness). Reduce it to a simmer and cook for 25 to 30 minutes. Pull a chicken breast out after about 20 minutes and cut it in half to check it's doneness, being careful not to cook the chicken too long.
Remove the fully cooked chicken and turn up the heat, bringing the liquid to a boil. Once boiling, add the noodles and cook for the length of time indictated on the noodle box.
While the noodles are cooking, shred the chicken.
Once the noodles are done cooking, remove the soup from the heat. Stir in the chicken and the heavy cream. Taste and add more salt and/or pepper to taste.