Prepare the marinade. In a small bowl, combine the oil, balsamic vinegar, water, lemon juice, garlic, salt, pepper, and Italian seasoning. Set aside.

Lay the vegetable slices in a shallow baking pan or baking sheet. Pour the marinade over the vegetables. Cover and refrigerate for at least two hours.

Preheat oven to 375 degrees Fahrenheit.

Layer vegetables, in alternating colors, in the cups of a muffin pan, ending with the red onion. I layered in the following order: 2 slices carrots, 2 slices yellow squash, 2 squares red pepper, 2 slices Portobello mushrooms, 2 slices zucchini, 2 squares yellow pepper, and red onion. The vegetable stacks will shrink as they bake, so stack generously.

Cover and bake for 15 minutes. Uncover and bake an additional 10 minutes. Keep in muffin tins until ready to serve. Remove carefully from muffin tins and place directly on serving platter. Can be served warm or at room temperature.