Layered Zucchini & Yellow Squash Casserole - yellow squash

Ingredients

• 2 medium yellow squash, thinly sliced
• 2 medium zucchini, thinly sliced
• 1 medium onion, thinly sliced
• 1/2 large green bell pepper, sliced in strips
• 1 cup fresh mushrooms, sliced
• 1 large tomatoes, sliced
• salt and pepper, to taste
• 2 tablespoons butter
• 2 tablespoons grated parmesan cheese