Preheat oven to 325°. Season chicken with salt. In a small sauce pot, bring broth to a boil and then lower heat to keep warm. Heat olive oil over medium heat in a paella pan or other thin, over-safe frying pan. Sear the chicken on all sides, adjusting the heat as needed. Rest chicken on a plate and set aside, covering loosely with aluminum foil.
Sauté onion and peppers, cooking until soft. Add garlic and cook until fragrant and lightly browned. Add chorizo, allowing the fat to render. Fry saffron briefly in the rendered fat. Add tomato, pimento, and paprika. Cook for 10 minutes or until tomato is softened. Slowly add hot chicken broth and wine, stirring until the rice has absorbed most of the liquid. Taste and season with salt and pepper. Bury chicken into rice and bake, setting pan on the bottom of the oven or the lowest possible rack. Bake for roughly 30 minutes, or until chicken is cooked through and rice has developed a gentle crust, adding the shrimp roughly 20 minutes in. Remove from the oven, cover with foil, and rest for 10 minutes. Garnish with parsley to serve in the paella pan.