In a medium saucepan, bring water to a boil over high heat. Stir in rice, salt and saffron, reduce heat to low, cover and simmer for 20 minutes or until rice is tender and water is absorbed. Remove from heat and stir in butter, fluffing rice with a fork. Let cool completely.
Meanwhile, in a medium skillet, heat oil over medium-high heat. Add onion and cook, stirring, for 5 minutes or until softened. Stir in tomatoes and paprika; cook, stirring, for 2 to 3 minutes or until tomato juice has evaporated. Let cool completely.
Layer onion mixture, rice, peas, chorizo, chicken, shrimp and parsley in jar. Seal jar and refrigerate for up to 1 day.
When ready to serve, remove lid and microwave on High for 3 minutes or until warmed through.