For this recipe, you will need a batch of fully cooked Bolognese sauce. This is a great way to use up leftover Bolognese sauce, but if you haven’t any or need to start from scratch, do that first.

Bring a large pot of salted water to a boil and add the lasagna noodles. Cook the noodles according to directions on the package, usually 12 minutes. Drain, rinse with cold water to stop the cooking process and set aside. If you’re not building your lasagna right away, lay the noodles out on a clean kitchen towel on a sheet pan.

Pre-heat the oven to 350ºF.

Combine the ricotta cheese, Parmesan cheese, egg, parsley, salt and pepper in a bowl until well blended.

Use a mandolin or sharp knife to thinly slice zucchini from stem to flower end into long thin slices, about ¼-inch thick.

Cover the dish with aluminum foil and transfer the dish to the oven for 60 to 75 minutes, until the lasagna starts to bubble around the edge. (If you are starting with cold Bolognese sauce, it will take longer to get to the bubbling stage.)

Remove the foil and cook an additional 15 minutes. Remove the lasagna from the oven and let it cool for 10 to 15 minutes. Then, slice into portions and serve with a side salad.