Bring a large pot of water to a boil. Cut the cauliflower into florets. Add the cauliflower to the boiling water and cook for 8-10 minutes or until fork-tender.

In a medium-sized skillet, add the butter over medium-high heat. Add the onion and garlic and cook until tender.

Remove the cauliflower with a slotted spoon and put it into a blender or food processor. Add in the garlic and onion, chicken broth, milk, parmesan cheese, and salt and pepper. Blend until smooth and no lumps are found.

Toss with fettuccini noodles and serve.