Thinly slice eggplant, place single layer on oil-sprayed pan sprinkle with freshly ground pepper, and broil for 5-10 minutes watching closely and flipping once.
Heat a large pan on medium. Add onion and garlic, saute in a small quantity of choice liquid. When onion is transparent add the rest of the vegetables except spinach (any combination will work, whatever you fancy. Cook until just slightly tender and most of the liquid evaporated. Add canned tomatoes and herbs. Cook another 3-5 minutes.
Coat the bottom of the lasagna pan with a little tomato sauce/vegetable liquid. Add a layer of broiled eggplant (should be crispy but not burnt). Top with sautéed vegetables, fresh spinach, eggplant, vegetables, etc. When layers run out, spread tomato/pasta sauce over top. Sprinkle with cheese if you desire. Bake uncovered at 350F for 35 minutes.
Serve with pasta, couscous, mixed salad greens, or crusty vegan bread.