Place the cleaned chicken in a stock pot large enough to hold the chicken and 10 cups of water (6 - 8 quarts pot). Add the garlic, ginger, onion, scallions, optional peppers and 10 cups of water (or enough to cover the chicken).
Bring it to a boil over high heat. Skim off any foam on top. Reduce the heat to medium and boil, covered, for about 40 - 50 minutes, depending on the size of the chicken. Cut through the thickest part of the breast, with a knife, to see if the chicken is cooked and tender.
Turn the heat off and carefully remove the chicken. When the chicken is cool enough to handle, remove the meat off the bones. Shred the meat into small bite size pieces. You can strain the broth, remove the excess fat and serve at this point. But, I put the bones back in the soup and boil again for more flavorful broth.
Optional Step: Put the bones back in the broth and simmer over medium low heat for an additional 30 minutes to an hour depending on how much time you have.
Strain the broth and remove the excess fat. You can spoon off the fat, refrigerate the broth until the fat solidifies, or use a fat separator.
To serve, place some rice in a serving bowl, add chicken pieces, and then ladle the hot broth on top. Typically, chopped scallions, salt and pepper are served separately so each person can season to taste. Serve piping hot with kimchi.