Wash and dry all produce. Core, seed, and thinly slice bell pepper. Halve, peel, and dice onion. Mince or grate garlic. Slice chorizo into ¼-inch-thick rounds.
Heat a large pan over medium heat. Add chorizo to pan and cook until it crisps and releases some of its oil, 1-2 minutes per side. Set aside, leaving oil in pan.
Season chicken on all sides with salt and pepper. Heat same pan over medium heat. (TIP: If pan seems dry, add a drizzle of oil.) Add chicken and sear until browned and cooked through, 5-6 minutes per side. Remove from pan and set aside.
Add onion, garlic, bell peppers, and a drizzle of oil to same pan over medium heat. Stir until just softened, 3-4 minutes. Add rice and stir to coat. Stir in 1 cup water, a pinch of salt, and chicken stock concentrate. Cover and reduce heat to low. Simmer until rice is tender, 15-20 minutes.
Meanwhile, cut lemon into wedges. Finely chop parsley. TIP: While you wait for rice to finish, try practicing this Spanish phrase: Con pan y vino se anda el camino (life is better with food and wine).
Fluff rice with a fork and season generously with salt and pepper. Place chicken on top and sprinkle with crispy chorizo. Remove pan from heat and sprinkle with parsley and a few squeezes of lemon.