Easy cheese soufflé

Ingredients

• 100 g butter
• 60 g flour
• 500 ml milk, cold
• 1 / 2 ts salt
• 1 / 2 ts pepper
• 6 eggs
• 200 g grated, full-flavored Gruyère cheese
• 1 bunch chives
• 50 g chopped Parmesan cheese