Cheesy Zucchini Delight Casserole

Ingredients

• 2 lbs (900g) zucchini, thinly sliced
• 1 medium yellow onion, finely chopped
• 2 cloves garlic, minced
• 1/4 cup (60ml) olive oil
• 1 teaspoon dried Italian seasoning
• 1/2 teaspoon salt
• 1/4 teaspoon black pepper
• 1 cup (240ml) sour cream
• 1 cup (240ml) mayonnaise
• 1 cup (100g) shredded cheddar cheese
• 1/2 cup (50g) grated Parmesan cheese
• 1/4 cup (30g) chopped fresh parsley
• 1/4 teaspoon garlic powder
• 1 cup (50g) panko breadcrumbs
• 2 tablespoons (30g) melted unsalted butter