Slice zucchini lengthwise into very thin slices. Cut tomato into thin slices.
In a large non-stick skillet over medium-high heat, mix ground beef, chopped onion, spinach, spices, and water and cook for 15 minutes.
To assemble lasagna, spread 1/3 of the meat sauce in the bottom of a Pyrex glass cooking sheet. Then layer 1/3 the zucchini slices, and 1/3 of the tomato slices. Repeat layering until you have used all the ingredients.
Bake for 45 minutes covered with foil. Let stand 5 minutes before serving.