Preparation

1. Pour the couscous in a bowl, dress it with a drizzle of oil and separate it using a fork.
2. In a saucepan, bring 600 ml of water to a boil with the stock-cube.
3. Turn the heat off and pour the broth on the couscous. 
4. Cover the couscous bowl with plastic wrap and let it rest for about 10 minutes.
5. Prepare the pesto.
6. Wash and dry the celery leaves.
7. Pour the celery leaves, the walnuts, the ricotta cheese and the salt in a blender. 
8. Add slowly the oil, until you achieve a creamy pesto.
9. Dress the couscous with the pesto, complete with the grated lemon rind and the dry tomatoes.