Prick the lemon all over with the point of a sharp knife. Place it in a wide pot or Dutch oven with the Parmesan rind, half of the basil, the garlic, and the Kosher salt. Pour 2 quarts of cold water into the pot and bring to a simmer.
While the water is coming up to a simmer, slice two of the zucchini into thin rounds, chop another two into centimeter dice, and grate the remaining two on the wide holes of a grater.
Stir the orzo into the simmering broth and cook for about 3 minutes. Add the diced and sliced zucchini to the orzo, stir and let simmer for five minutes, stirring and scraping the bottom of the pot occasionally, before adding the grated zucchini. Continue to simmer until the orzo is cooked and the zucchini is translucent, another minute or two.
Fish out the sticky Parmesan rind and spent basil and discard them. Pick the leaves off the remaining basil stalks, tear and stir through, Press the lemon to release some of its juice. You could get rid of it, but I think it looks rather beautiful in the pot.
Pour in the olive oil and stir it through. Taste for salt, then drop a dollop of creme fraiche into the pot. Grind black pepper over everything and finish with a drizzle of olive oil.
There may be crisp orzo at the bottom of the pot. Devour it with delightfully sloppy spoonfuls!
