Place the couscous in a bowl; stir the warm chicken broth and 2 tablespoons olive oil into the couscous. Add the tomatoes, red onion, green onions, cucumber, parsley, and lemon juice. Cover the bowl with plastic wrap and allow to steam for 5 minutes. Uncover and fluff the couscous with a fork. Stir to mix the vegetables evenly through the dish. Season with salt and pepper to serve.