Step 1

Preheat the oven to 375°F. Coat a 2 1/2-quart casserole dish with cooking spray.

Step 2

In a large skillet heat the butter and olive oil over medium-low heat. Add in the onions and cook for 3 minutes or so (don’t let them brown). Add in the peppers and garlic and continue to cook for an additional 3 minutes. Add in the mushrooms and cook them until they start to release their moisture (about 3 to 4 minutes). Finally, add in the tomatoes and herbs and allow to simmer for a couple of minutes. Remove the mixture to a large bowl and set aside.

Step 3

In the same skillet, heat the vegetable oil and then add the eggplant and salt. Allow the eggplant to cook until it’s browned, stirring frequently. Once lightly browned add in the flour and stir. Add the tomato mixture and stir everything together and bring it to a simmer.

Step 4

Spoon in 1/3 of the vegetable mixture into the prepared baking dish. Top it with some Parmesan cheese and a few slices of mozzarella. Spoon more of the veggies on top of the cheese followed by more cheese. Spoon in the last of the mixture and top it all of with a layer of cheese on top.

Step 5

Bake the casserole for 30 minutes. Allow the casserole to stand a few minutes before serving.