Mix milk, onion (whole or 2) nutmeg , cloves and bay leaf in a saucepan over low heat and simmer gently for 15 minutes, open to flavored milk. Discard the onion, bay leaf and cloves. Meanwhile, melt 4 tbsp butter in a pan over low heat. Add 4 tbsp flour. Cook without a lid, stirring occasionally with a wooden spoon or spatula, medium low heat 2-3 minutes. Remove from heat and slowly stir in the milk, pour in 1/2 cup at a time. Simmer for 8-10 minutes, do not boil. Season with salt and pepper.