Wash the (pearl) barley under cold running water until it runs clear. Place in a saucepan and cover it with three times its volume of water. Bring to a boil over medium heat, then let simmer for 30 minutes. Remove from the heat and let cool. Once the barley has reached room temperature, drain and refrigerate until ready to prepare the salad.
Mix the barley with the pomegranate seeds and basil.
In a bowl, whisk the oil with the lemon zest and juice, ground pepper, and salt to taste. Just before serving, mix the dressing into the salad and adjust the seasoning before serving.