Preheat the oven to 425° F. Begin by thinly slicing the 3 zucchinis into long ¼ inch thick slices. I like to do this with a mandoline slicer, but you can also use a sharp knife. Salt both sides of the zucchini with around 1/4 tsp of salt and let it sit on a stack of paper towels for at least 10 minutes. Blot the zucchini with a paper towel to remove as much of the extra moisture as you can. This is an important step because zucchini has a lot of water. Skipping this step may cause you to have a watery lasagna.
Lay the zucchini lengthwise on a sheet pan and roast it in the oven for around 10-15 minutes or until it starts to brown. This will remove the excess moisture and make the zucchini more like a “noodle”. Remove the zucchini from the oven and set it aside until you’re ready to assemble the dish.
Meanwhile, heat a large cast iron skillet over medium-high heat. It’s important to pre-heat cast iron to give it its non-stick qualities. Brown 1 pound of sausage and 1 pound of ground beef together with the chopped onion and 2 minced garlic cloves. Add ½ tsp of salt to the meat mixture. After it’s cooked drain off any excess fat.
Add 2 cups tomatoes, 6 ounces tomato paste, ¼ cup basil, finely chopped bell pepper,1 tbsp parsley flakes, 1 tsp salt, and 1 tsp pepper to the meat mixture. Mix everything together well. Cover the pan and simmer it on low heat for around 20 minutes until all the flavors blend.
While the meat mixture simmers, combine 24 ounces cottage cheese, 2 beaten eggs, 2 tbsp parsley flakes, ¼ tsp salt, and ½ cup parmesan cheese in a separate bowl.