Heat the olive oil in a skillet over medium heat. Add the garlic and sauté for a minute or two, being careful not to let it burn.
Bring the stock to a boil and add the cauliflower. Cover and cook for 5-6 minutes until the cauliflower is tender. Transfer the cauliflower, including liquid, to a blender and blend until smooth. Add the cheese and continue blending. You can add more stock or milk to thin the sauce to your liking. Season with salt and pepper before serving.