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Bahan-bahan (12 porsi)

• 3 tablespoons unsalted butter, (melted and slightly cooled)
• 5 large eggs
• 1½ teaspoons salt
• 1½ cups milk
• 1½ cups all-purpose flour, (spooned into measuring cup and leveled-off)
• 3 oz Gruyère cheese, (finely shredded (optional but recommended; about 1 cup))