Preheat oven to 450 degrees F. Place the chicken on a baking sheet and roast until browned, about 20 minutes.
Coat a large stock pot with olive oil and add the onions, celery and carrots. Season with salt to taste and bring the pot to medium-high heat. Cook the vegetables until they start to soften and are very aromatic, about 10 minutes. Add in the garlic and crushed red pepper and cook for another 2 to 3 minutes. Add the chicken and fill the pot with the chicken stock and enough water to cover the chicken. Squeeze the juice of the 2 lemon halves into the soup and drop in the lemon halves. Add the bay leaves, thyme and potatoes and bring the ingredients to a boil, then reduce the heat to a simmer.
Cook for 30 minutes, skimming off any particles that accumulate on the surface. Use tongs to remove the chicken to a cutting board. Let the chicken cool, then remove the bones and discard. Pull the meat into bite-sized pieces and return them to the pot. Stir in the corn and cinnamon and taste for seasoning. Adjust the flavors with salt and pepper, if needed.
Discard the lemon halves, thyme and bay leaves. Taste the soup for seasoning, which should be spicy with a bright lemon flavor.
Ladle the hot soup into serving bowls. Garnish with cilantro leaves and serve. This soup is perfect for a cold day! YAY!