Prepare Zucchini: Trim the ends of the zucchini and slice them lengthwise into ¼-inch-thick planks. Preheat your grill or broiler to medium-high heat, and grill or broil the zucchini slices for about 2-3 minutes on each side until lightly browned.

Cook Beef: In a large skillet, heat a tablespoon of extra-virgin olive oil over medium-high heat. Add the ground beef or bison along with a sprinkle of kosher salt and dried oregano. Cook for about 5-7 minutes until browned. Add minced garlic and sauté for an additional minute before adding marinara sauce to simmer.

Combine Cheese Filling: In a mixing bowl, blend together the cottage cheese, ¼ cup of grated Parmesan, the large egg, and remaining kosher salt and black pepper. Stir in the thawed chopped spinach until well combined.

Assemble Lasagna: Grease a 9x13-inch baking dish. Layer half of the meat sauce, half of the grilled zucchini, and all of the cheese mixture. Repeat with remaining zucchini and meat sauce. Top with shredded mozzarella and rest of the Parmesan.

Bake: Preheat oven to 350°F, then bake the assembled Zucchini Lasagna for 20 minutes until the cheese is melted and bubbly. Let rest for 5-10 minutes before serving.