Spinach, Potato, and Zucchini Soup

A few weeks ago, I used my last Barnes and Noble Christmas Gift Card to buy Anna Thomas's Love Soup (Fab Ebert-penned interview on the awesomeness that is Anna Thomas here).  I've been reading Love Soup on and off over the past few weeks for inspiration, but this is the first recipe I have more or less test piloted.  Just as I do in all my recipes ganked from cookbooks, I basically tailored this dish to whatever I had lying around.  Where I used frozen spinach, Anna used fresh basil, where I used garlic broth, Anna used light vegetable broth, and, finally, I admit I used cilantro for her parsley.

1 large potato, diced
1 medium zucchini, diced
1 pint of potato peel broth
2 heaping tablespoons of pesto (I like Classico's jarred version, it has a good deal of olive oil and garlic)
10 oz of frozen spinach or 1 package (I find frozen spinach is less stringy when it cooks down in soup)
cilantro, lemon juice, pepper, and salt to taste

Defrost the frozen spinach.  Pour potato peel broth into your soup pot and slowly bring to a boil.  Add the chopped potato, and simmer until it gets tender.  Then add the zucchini and frozen spinach.  Stir in the pesto and then add your cilantro, lemon juice, pepper, and salt to taste.