Creamy Green Bean Casserole from Scratch

Bahan-bahan (8 porsi)

• 1 medium onion
• 1/2 cup (62g) all-purpose flour (spooned & leveled)
• 3/4 cup (45g) panko breadcrumbs*
• 1/2 teaspoon salt
• 1/4 teaspoon ground black pepper
• 1 large egg
• 1 Tablespoon (15ml) milk
• 1 Tablespoon + 1 teaspoon salt, divided
• 1 pound fresh green beans, rinsed, ends trimmed, and halved
• 2 Tablespoons (28g) unsalted butter
• 8 ounces sliced mushrooms*
• 1/2 teaspoon ground black pepper
• 2 cloves garlic, minced
• 2 Tablespoons (15g) all-purpose flour
• 3/4 cup (180ml) chicken or vegetable broth
• 1 and 1/4 cups (300ml) half-and-half*