Preheat oven to 450°F. Coat inside of a 4-quart dutch oven with a neutral-tasting oil.
Rinse rice until water comes out clean, then pour into the dutch oven. Add broth and stir.
Arrange chicken on top of the rice, and season with salt and pepper.
Slice 1 lemon into rounds and arrange on top of chicken. Add the zucchini and garlic on top of the lemon.
Halve the other lemon and juice half over the top, reserving the other half for serving, if desired. Top with rosemary sprigs and cover.
Bake in oven for 35-40 minutes.
* If it's too late in your area for zucchini, butternut squash will do as well, but do not squeeze lemon juice over the top.* Meyer lemons are milder and more delicate than regular lemons, but feel free to use regular lemons if you can't find them.