Preheat oven to 375 degrees F. Spray a deep 9x13” casserole dish with cooking spray or rub well with olive oil and set aside.
Slice zucchini lengthwise into very thin slices or use a mandolin to do so. Lay all of the slices onto a paper towel (somewhere in the kitchen that it won’t take up prep space) in one layer and sprinkle lightly with sea salt; leave them be while you prep the sauce.
To start the sauce, heat olive oil in a large skillet over medium heat. Once warm, place the ground meat into the skillet and break up. Cook for approx. 7 minutes – until almost cooked through. Set aside.
In a separate sauté pan, add the green pepper and onion; cook until softened – approx. 5 minutes; add in mushrooms, garlic and a pinch of sea salt. Cook for another 2-3 minutes, stirring constantly so the garlic doesn’t burn.
Add the vegetable mixture to the meat and stir in tomato paste, tomato sauce, wine, basil, and oregano. Add a small amount of hot water or broth if sauce gets too thick. Bring to a light boil; reduce the heat and simmer sauce for approximately 20 minutes, stirring every few minutes.
While the sauce is cooking, whisk (or use a hand mixer) the egg, goat cheese, and parsley together in a bowl until completely combined. It should have the texture of a thick sauce.
To assemble the lasagna, spread ½ of the meat sauce into the bottom of casserole dish; then layer ½ of the zucchini slices, all of the goat cheese mixture, and then repeat with zucchini and then sauce again. Cover with foil.
Bake for 20-25 minutes. Remove the foil and sprinkle the top with the goat cheese crumbles. Raise the oven temperature to 425 degrees F and bake an additional 5-10 minutes. Let stand for 5-10 minutes before serving.