Ingredients

• 1 tablespoon butter
• 1 tablespoon olive oil
• 1 large onion, diced
• 2 cloves garlic, minced
• 1 tablespoon fresh thyme
• salt and ground black pepper to taste
• 1 sheet frozen puff pastry, thawed
• 1 pound tomatoes, sliced into 1/4-inch rounds
• ½ cup grated Parmesan cheese, or more to taste
• ½ cup panko bread crumbs
• ½ cup crumbled feta cheese
• 1 tablespoon fresh parsley
• 1 egg, beaten
• 2 tablespoons thinly sliced fresh basil