Cook the zucchini onions garlic and 2 tablespoons olive oil in a large saut pan over medium heat for 10 minutes until the zucchini is tender Season with salt and pepper
Brush the red and yellow peppers and eggplant with olive oil season with salt and pepper and roast on a baking sheet for 30 to 40 minutes until soft but not browned
In a 6-inch round cake pan place each vegetable in a single overlapping layer sprinkling Parmesan cheese and salt and pepper to taste between each of the layers of vegetables
Begin with half of the eggplant then layer half of the zucchini and onions then all of the red peppers then all of the yellow peppers then the rest of the zucchini and onions and finally the rest of the eggplant
Cover the top of the vegetables with a 6-inch round of parchment paper or waxed paper Place a 6-inch flat disk another cake pan or the bottom of a false-bottom tart pan on top and weight it with a heavy jar Place on a plate or baking sheet it will leak and chill completely
Drain the liquids place on a platter and serve at room temperature