Place the potato and garlic clove in a saucepan and cover with cold water. Bring to a boil and boil 5 minutes. Add the broccoli and boil another few minutes until potato is tender. Drain and return vegetables to the saucepan.
Add the milk and mash well with a potato masher. Add the Parmesan and keep mashing until the consistency is how you like it. Taste and season with salt and pepper.