Peel and slice eggplant and place on rack. Sprinkle with salt and allow liquid to be pulled out as you prep rest of ingredients.
Dice the onion into ¼ inch pieces.
Wash and grate zucchini.
Slice cheese into ¼ inch slices. (Doesn’t have to be exact).
Peel and seed tomatoes by plunging into boiling water for about a minute and the skin splits, cool immediately in ice water, then slip off skins and cut tomatoes in ½. Squeeze each half gently to remove seeds.
Dice tomatoes to ½ inch cubes
Heat a heavy pan and add the olive oil. While it is heating press the eggplant slices into the breadcrumbs. Sautee until golden brown on both sides over medium high heat. Make sure that oil is hot before adding eggplant.
Remove and place on paper towels to drain. Add rest of veggies to hot pan and continue to cook over medium heat until a marinara sauce is achieved. Lower the heat a bit for this step.
Layer the sauce, eggplant, and cheese, starting with sauce and ending with cheese in a lasagna pan or deep oblong baking dish. Back at 375 degrees until cheese is bubbly and lightly browned. (About ½ hour). You can prep the day before and bake off the next. Just double the baking time.
Let rest about 10 minutes for easier cutting and serving. I know this seems a bit complicated but it is much easier than it reads as you will see and the final product is worth it.