Bring 2 cups of water to a boil in a large saucepan. Add the barley, cover, reduce the heat, and simmer until tender about 20 to 40 minutes. Drain and rinse with cold water. Transfer to a large bowl.
Stir in the parsley, carrot, cucumber, cheese, oregano, radicchio, olive oil, lemon juice and salt. Mix to combine and set aside.
Cut the tops oﬀ the tomatoes and reserve. Hollow out the pulp, cube it and mix it into the barley mixture. Stuﬀ the tomato cavities with the mixture and replace the tops.
Serve or refrigerate until needed. Bring to room temperature before serving.