In the same pan, make a sofrito by sauteing the onions, garlic and parsley. Cook for 2 to 3 minutes on medium heat. Add tomatoes and cook until mixed, about 5 to 10 minutes. Fold in the rice and stir fry to coat the grains. Pour in water and simmer for 10 minutes stirring occasionally. Add chicken, chorizo and saffron. Add the shrimp and peas on top, cover with tin foil and let it cook for 15 minutes. Remove from heat and let sit, still covered, for at least 5 minutes.