Cut 1/2 half of the mushrooms into quarters and reserve. Finely mince remaining portion. Heat olive oil in a heavy Dutch oven over medium heat. Add onion and minced mushrooms. Cook 10 minutes or until onions are very soft, stirring frequently. Add garlic and mushroom quarters and cook 5 minutes, stirring constantly. Add remaining ingredients, stir and bring to a simmer.
Reduce heat and simmer 20 minutes, stirring frequently.
Sliced Zucchini lengthwise into 1/4" thick slices. Sprinkle sliced zucchini with salt, pepper, basil and oregano.
Heat 1 tablespoon of olive oil in a large skillet over medium heat.
Place zucchini slices in one layer in the pan. Saute about 3 minutes per side just until tender. Remove to heated platter and cover to keep warm while sauting remaining zucchini.