In a small saucepan, gradually stir milk into cornstarch until smooth. Add butter, salt, pepper and nutmeg. Stirring constantly, bring to boil over medium heat; boil 1 minute to thicken. Add cheese and stir until smooth. Keep hot. Poach eggs by bringing 3 inches (8 cm) of water to a boil. Reduce to a gentle simmer. Break cold eggs, one at a time, into a small dish. Gently slip eggs into water. Cook in barely simmering water 3 to 5 minutes. Remove eggs with a slotted spoon and drain well. Place two muffin halves on each of 4 dinner plates. Top each muffin half with a slice of ham, a poached egg and 2 tbsp (30 mL) cheese sauce. Garnish with shredded cheese and parsley. Serve immediately.