This is a classic consommé that I learnt in my college days. At home, no one can really be bothered to go to the trouble of making a clear soup, but if you use the simple method in the recipe above you'll find it considerably easier. Julienne is a culinary term for finely-shredding vegetables into matchstick-like pieces which you can do on a mandolin or by cutting with a very sharp knife.
The stock from above
1 medium carrot, peeled, trimmed and cut into 3cm-long matchstick strips
A couple of sticks of celery, peeled if necessary and cut into 3cm-long matchstick strips
1 small or half a leek cut into 3cm-long matchstick strips and washed
The two chicken thighs from above, finely shredded
Bring the stock to the boil, add the vegetables and simmer for a minute or so until just cooked, then add the chicken and serve.