Bring chicken stock to a boil in saucepan.
Place couscous in large mixing bowl and stir boiling stock over. Stir and let rest about 15-20 minutes, or until all the stock has been absorbed. Fluff with a fork. Fold in toasted pecans and set aside.
Meanwhile, place parsley, oil, lemon juice, oregano and salt and pepper in a small mixing bowl and whisk together. Add tomatoes and crumbled feta cheese.
Pour dressing mixture over couscous, stirring to combine. Taste and adjust seasoning.
Chill 30 minutes prior to serving.