Roughly chop the cauliflower into pieces that will fit into feed tube of your food processor; process cauliflower using the large grating/shredding blade (if you don't have a food processor, see note).
Place grated cauliflower into a microwave-safe bowl.
Stir in olive oil and cover bowl tightly with plastic wrap.
Microwave on high for 3 minutes.
In a large skillet, melt butter over medium heat.
Add garlic and stir until fragrant (about 30 seconds).
Stir in cooked cauliflower and saute for about 2 minutes.
Remove from heat and add parmesan cheese; stir to combine.
Serve immediately.
Notes
If you don't have a food processor, you can grate the cauliflower using the large grate option on a box grater.