Ok, I confess that I served this with grilled Italian sausage but this eggplant parmesan is completely vegetarian and would be great served with pasta and a salad. Incidentally, salting the eggplant is not mandatory but it does reduce the likelihood of its being bitter and, in my opinion, concentrates its flavor.
1 large eggplant
Kosher salt and freshly ground black pepper
Extra virgin olive oil
1 medium onion
1 bell pepper
4 to 6 mushrooms
2 Tbsp. dry vermouth
2 cups tomato sauce, homemade or from a jar
½ pound mozzarella, sliced
Chopped Italian parsley leaves
Trim the eggplant and cut ¼-inch thick slices from the center reserving the short slices from the sides for another use. Lay the slices on a rack over a sheet pan and sprinkle generously on both sides with kosher salt. Set aside for about 30 minutes.
Peel the onion, halve through the root, and slice into thin semicircle. Cut the top and bottom off the pepper, remove seeds and ribs, then slice into thin strips. Clean and slice the mushrooms. Warm the tomato sauce.
Place a rack 4 inches below the broiler and preheat. Rinse the eggplant slices well to remove the salt then dry on a kitchen towel. Clean and dry the sheet pan and lay the eggplant slices in a single layer. Brush lightly on each side with olive oil and put under the broiler for 4 or 5 minutes on each side or until just starting to color. Remove and set aside to cool.
While the eggplant is roasting add olive oil to a fry pan and sauté the onions and peppers until soft. Season with salt and pepper to taste and set aside. Add a bit more oil and perhaps a bit of butter to the pan and add the mushrooms. Sprinkle with a bit of salt to help draw out their moisture and sauté until nicely browned. Stir in the vermouth and let boil down. Set aside.
Turn oven on to 325° (300° for convection). Choose a shallow, oven-proof pan wide enough to accommodate the eggplant slices crosswise. Spread a bit of tomato sauce thinly in the pan and layout the eggplant slices. Cover with a bit more tomato sauce. Spread on the onions and pepper, then the mushrooms, and a more tomato sauce. Arrange the mozzarella slices to cover the dish and top with the remaining tomato sauce. Sprinkle on the parmesan and the parsley leaves. Bake until browned and bubbly, about 20 minutes.