The Ultimate Potato Gratin

Name: The Ultimate Potato Gratin
Ingredients: 1.5 kg Potatoes (maris piper/king Edwards); 1 Onion; 4 cloves garlic; 20 g Fresh thyme; 568 ml Milk; 600 ml Double cream; 80 g Parmesan (plus extra for on top); 0.25 tsp Nutmeg; 1 tsp Salt; 1 tsp Black pepper

Slices of potato cooked with cream, garlic, and Parmesan cheese