Fill a large saucepan 3/4 full with water, salt the water lightly and bring water to a boil. Add 1/2 of the cauliflower florets to the boiling water; boil until tender. Drain well.
Melt butter in a 4 quart soup pot over a medium-low heat. Saute the onion and garlic in the butter until the onion is tender. Pour in the vegetable stock and unboiled cauliflower florets. Mix in nutmeg and bring the mixture to a boil; boil until cauliflower is tender. Remove pot from heat to cool.
Use an electric blender to blend the soup-onion-cauliflower mixture until smooth (blend the mixture 2 cups at a time). Place the blended soup back in the 4 quart soup pot and heat over a medium-low heat. Pour milk into the pot and stir well. When the mixture is simmering, mix in the cooked florets and 1 1/2 cup of cheese. Stir until cheese melts and the soup has thickened. Serve hot, season with sprinkles of cheese and black pepper to taste. .