Juice the 2 lemons into a small boil, then add salt, pepper, olive oil, and balsamic (optional, Giada's recipe didn't include it but my version does, how much you use depends on the grade/strength of your balsamic) and whisk together to make the dressing; set aside.
Get a large, decorative serving bowl and put the prepared endive, apple, and avocado into it.
Squeeze the juice from the additional 1/2 lemon over the endive, apple, and avocado and toss well- this will keep them from turning brown.
Add the cheese, cranberries, pomegranate seeds (if using), and corn.
Just before serving, whisk the dressing again then pour it over the salad and toss to coat.