Deep dish baking pan (I used Reynolds Kitchen Disposable Baking Pan with lid)
Set oven to 420F.
Set a nonstick skillet on medium high heat, add olive oil, garlic and chopped onion. Sauté and brown the onions, being careful not to burn the garlic.
Increase the heat of the skillet and add the ground beef. Chop up as it cooks with the onions. Sprinkle in Italian seasoning and sea salt & pepper and continue cooking until the meat is well chopped in the skillet (note: it is ok if there are still pink pieces).
Add the marinara and fold everything together. Reduce the heat to low, then simmer and cook for about 15 to 20 minutes to allow the flavors to meld.
In a separate bowl, mix together ricotta and egg whites. Set aside.
Using a mandolin (recommended) or a sharp knife, slice the veggies vertically into strips, slightly thicker than a nickel. (Pro-Tip: Pat the veggies dry on a paper towel and allow them to rest on the paper towels for about 20 minutes or even overnight in the fridge. This will help reduce the amount of water in the lasagna since veggies hold a lot of water.)
Build the lasagna. In a baking pan, add a layer of squash >> the meat sauce >> half of the ricotta mixture >> sprinkle of parmesan >> layer of eggplant >> meat sauce >> ricotta mix >> sprinkle of parmesan >> zucchini >> remaining meat sauce >> mozzarella
Cover with foil, then bake for 35 to 40 minutes. For the last 5 minutes, remove the top foil to allow the top to brown.