1. Rinse the quinoa several times.
2. Pour into a saucepan and add 2 times its volume of water.
3. Bring to a boil, reduce heat and cook for 10 minutes.
4. Meanwhile, cook the egg in a saucepan of boiling water for 10 minutes.
5. At the end of cooking, strain the quinoa under water to cool and drain the quinoa.
6. Wash and cut the tomatoes into pieces.
7. Finely mince the onions.
8. Chop the basil.
9. Peel the boiled eggs.
10. Cut the feta into pieces.
11. In a bowl, mix everything.
12. Serve.