Heat the olive oil in a large Dutch oven over low heat. Add the onion, garlic, carrots, and bell pepper and cook for 8-10 minutes until the onions are soft. Add the chicken breasts and cook for 4-5 minutes per side. Add the lemon and cook for 3 minutes, stirring occasionally.
Add the remaining ingredients except the parsley and add barely enough water to cover everything in the pot. Bring to a boil, and then turn the heat to a simmer. Cover and cook for 50-60 minutes, stirring occasionally. Add more water if necessary. Serve warm, topped with fresh parsley.