Rinse and drain the chicken. Place the chicken in a large pan, add water and salt, spices and herbs and bring to a boil. Reduce the heat and simmer. After 20 minutes, add the onion,celery,and carrots. Add potato chunks or rice if desired. (Do not add rice or potatoes if you are making chicken and noodles. Do not add noodles yet.) Continue simmering for another 20 minutes or until the chicken is cooked. When chicken is tender, turn the heat off. Remove chicken to a large platter or bowl, remove the skin and discard, and let the chicken cool enough that you can debone the meat-about 15 minutes. Remove the meat from the bones and cut into chunks. You will want 2-3 cups of boneless chicken. Skim the fat from the chicken broth and vegetables and discard. Place flour into a small bowl or large cup. Remove about one cup of broth from the pan. Add a little broth to the flour, stir the flour to moisten, and then add more broth a little at a time until the entire cup of broth is added, stirring after each addition to remove lumps. Slowly stir the flour mixture into the broth. Add the chicken chunks. Add the 2 cups of milk. Bring to a simmer, stirring occasionally until the soup has thickened. If you are adding homemade noodles, flour from the noodles will further thicken the soup. Add the noodles if you are adding noodles. Add the peas. Continue cooking until tender. Serve hot.
For dumplings: In a medium bowl, mix the flour, baking powder, and salt together. In a small bowl or large cup, whisk the oil and milk together. Form a depression in the flour mixture and add the liquid mixture. Stir with a fork until combined. With a large spoon, drop mounds of dough atop the bubbling soup. The soup must be bubbling hot to start the cooking of the dumplings upon contact. Immediately cover the pan. Reduce the heat so that the soup will simmer and let cook for about ten minutes. The dumplings are cooked when a toothpick inserted in the center comes out clean. Serve hot.