just made this tonight, and it was very good, with some additions. I used leftover roasted chicken instead of cooking up fresh chicken breasts. Also sauteed 1 sweet onion in olive oil, then added 1 sliced carrot, 1/3 cup white wine, and 6 cups broth. I combined the egg and lemon in the food processor, then ladled off 1 cup of the broth and slowly poured it into the egg-lemon mixture with the processor running. Added baby spinach, 2 tsp fresh thyme, and 3 Tbsp fresh parsley, finely chopped.
This was actually really great. The lemon really gave a nice kick to the broth, and such a healthy addition. I used rice instead of orzo which also worked nicely.