Method:
Heat oil in a large pot over medium high heat. Whisk together flour, salt and red pepper flakes in a medium bowl then coat chicken with flour mixture, shaking off any excess. Transfer chicken to pot and cook, stirring occasionally, until browned; transfer to a large plate and return pot to the heat. Reduce heat to medium, add onion and garlic and cook until softened. Add tomatoes, broth and browned chicken and simmer, covered, for 45 minutes.
Meanwhile, melt butter in a large skillet over medium high heat, add mushrooms and cook until tender and golden. Sprinkle with lemon juice and set aside.
Add cooked mushrooms, basil and parsley to pot with chicken mixture and continue simmering just until heated through. Spoon into bowls and serve.