Season chicken, if desired with salt and pepper. Heat oil in large deep skillet over medium-high heat and brown chicken. Remove from skillet and set aside.
Cook chorizo in same skillet, stirring occasionally, until lightly golden, about 3 minutes. Stir in onion and cook, stirring occasionally, until very tender and starting to brown, about 4 minutes. Stir in rice and cook, stirring frequently, until rice begins to turn golden, about 4 minutes.
Stir in water and Knorr® Mi Arroz™ Red Rice Seasoning Mix. Bring to a boil over high heat. Reduce heat to low and simmer covered 12 minutes.
Arrange chicken, shrimp and peas over rice. Cook until chicken is thoroughly cooked, shrimp turns pink, liquid is absorbed, about 8 minutes. Remove skillet from heat; let stand 5 minutes.