This savory vegetarian lasagna is easy to put together You can assemble it up to a day ahead of time, then bake it shortly before dinner.
Source: Lasagna with Chard, Tomato Sauce and Ricotta Recipe – NYT Cooking
Squash and Broccoli Rabe Lasagna Recipe – Bon Appétit.
This recipe seems a little more complicated, but damn does that look good..
Noodle-less Zucchini Lasagna Recipe | Epicurious.com.
This recipe calls for ground beef. If you are veg, then you could substitute soy crumbles, chopped portobello, or just go without.