Add the shallots and cook until fragrant, 1 to 2 minutes.
Add the garlic and cook 1 minute more.
Add the orzo and stir to combine, then add water and bring to a simmer. Cook, stirring occasionally, until the water has been mostly absorbed into the pasta, 3 to 4 minutes
Begin to add the broth gradually, as you would for risotto: about 1 cup at a time, waiting to add additional broth until the prior cup has been fully absorbed, until the orzo is completely tender (12 to 15 minutes).
Stir in the spinach and let it wilt. Stir in the lemon zest, lemon juice, butter and Parmesan cheese. Season with salt and pepper. Serve immediately. Yields: 4 servings.