Put the chopped eggplant into a bowl and add a 1 tbsp salt. Let stand for 30 minutes. Then rinse well and drain all of the liquid.
Do the same salting, with 1 tbsp, and rinse for the squash.
Sauté the eggplant in a large frying pay with about 1/3 cup water, stirring frequently until softened. Watch it carefully and replace water if it gets too dry. Add 1/2 tbsp salt and 1 t/2 tbsp pepper and then add to a large casserole dish.
Sauté the squash just like the eggplant, with a little water until almost soft. Add remaining salt and pepper and then add to the casserole dish.
Add the tomatoes to the pan and sauté with the onion and peppers for about 10 minutes.
Add the fresh herbs. If you want less water, sauté until most of the water is gone.
If using mushrooms, add them to the tomato mixture and heat them through.
Add the tomato mixture to the large casserole dish and mix together with the other vegetables. Cover and bake for 30 minutes.
Serve with rice or quinoa.