Vegetarian Stuffed Portobello Mushrooms

Ingredients

• 2 small yellow squash, thinly sliced
• 2 small zucchini, thinly sliced
• 2 small green bell peppers, thinly sliced
• 1 small onion, thinly sliced
• 3 tablespoons olive oil, divided
• 1 tablespoon balsamic vinegar
• 3 tablespoons garlic and herb seasoning blend (such as Mrs. Dash®)
• 4 large portobello mushroom caps
• 1 cup shredded Parmesan cheese
• 1 1/2 cups shredded mozzarella cheese
• 1 tablespoon chopped fresh parsley
• 1/4 cup pineapple chunks