Gather all the ingredients.
Finely dice onions and set aside.
Grate garlic with a grater or mince and set aside.
Slice Cremini or Bella Mushrooms and set aside.
Loosely chop langoustine tails and set aside.
Melt butter in a large skillet over medium heat.
Add onion, garlic and mushrooms cook until tender. About 2-3 minutes.
Add langoustine tails and stir to combine.
Stir in cauliflower and cook until tender, approximately 3 minutes.
Stir in heavy cream, Parmesan cheese, salt, pepper and nutmeg. Cook 5-7 minutes.
Top with shredded Parmesan cheese and serve hot!