Prepare the Chicken: In a large pot, add chicken pieces and cover with water or chicken broth. When it reaches a boil, reduce the heat and simmer for about 30 minutes, skimming off any foam or impurities that rise to the top.
Add the Vegetables: Return the carrots, yam and sweet potatoes to the pot. Sauté the onion and garlic, stirring to combine. Let the mixture simmer for approximately 30 minutes or until the vegetables soften.
Make the Dumplings: Once the soup is simmering, make the dumplings. Combine flour, water (scant 1/4 cup) and salt in a bowl. Work it into a dough in a bowl and roll it into small balls. Set aside.
Season the Soup: Add the thyme, the pimento seeds and the whole scotch bonnet pepper (if you want it mild). Add salt and pepper to taste. Give a stir, and let the soup simmer some more.
Add the Dumplings: Skim the prepared dumplings over the pot, spacing them out evenly. Allow them to simmer in the soup for 15 to 20 minutes or until floating and cooked through.
Finishing Touches: Take the chicken out of the pot when it is tender. Shred the chicken and put it back into the pot, discarding the bones—season with more salt and pepper as necessary.
Serve: Ladle the soup into bowls, ensuring each serving gets a generous amount of chicken, vegetables, and dumplings. For extra heat, slice the scotch bonnet pepper into the soup. Serve hot with crusty bread or crackers.