Heat butter and olive oil in a large pot.Add onion, celery and carrot and cook stirring for about 3 minutes, add garlic and cook for one more minute.Add salt, pepper and dried oregano or thyme.Add chicken broth and bring to a boil.When soup is boiling add uncooked noodles and cook for approximately 8 minutes.Meanwhile in a small saucepan, over medium heat, melt butter and add flour, stir the mixture constantly for about 3 minutes.Slowly add the milk to the flour and butter mixture, whisking constantly until the milk comes to a boil.Pour the creamy milky mixture into the soup, stir, reduce heat and simmer until slightly thickened, about 2 minutes.Stir in the shredded chicken and peas and simmer for 1 more minute.Adjust seasoning, add a dash of freshly grated nutmeg and a sprinkling of chopped parsley if desired.Serve.