Step 1

Trim both ends off the zucchini.

Step 2

Use a mandoline to cut the zucchini into 1/8 inch slices. Sprinkle salt over the zucchini slices, then lay them out on a layer of paper towels to drain. Let sit for at least 10 minutes.

Step 3

Pat the tops of the zucchini slices with paper towels until dry.

Step 4

While the zucchini is resting, prepare the sauce. Heat the olive oil in a large pan over medium heat.

Step 5

Add the ground beef and season with salt and pepper to taste.

Step 6

Cook for 5-6 minutes, breaking the meat up with a spatula, until beef is browned and cooked through.

Step 7

Add the onion and cook for another 3-4 minutes or until softened. Add the garlic and cook for 30 seconds.

Step 8

Add the marinara sauce and bring to a simmer; cook for 5 minutes.

Step 9

Place the ricotta cheese, Italian seasoning, egg, parmesan cheese, salt and pepper in a bowl. Mix until well combined.

Step 10

Preheat the oven to 375 degrees F. Coat a 2 or 3 quart baking dish with cooking spray.

Step 11

Place 1/4 of the sauce in the bottom of the dish. Add 1/3 of the zucchini slices on top. Spread 1/3 of the ricotta mixture over the zucchini then top with 1/3 of the mozzarella cheese. Repeat the layers, ending with the mozzarella cheese.

Step 12

Cover and bake for 30 minutes. Uncover and bake for an additional 20 minutes. Sprinkle with parsley, then let stand for 5-7 minutes. Cut into slices, then serve.