Cream Mixture: Place butter, cream and garlic in a jug. Mix until combined.
Preheat oven to 180°C/350°F (both fan and standard ovens).
Slice potatoes: Peel the potatoes and slice them 1/8″/3 mm thick. Or use a slicer!
Layer 1: Spread 1/3 of the potatoes in a 1.5 litre / 6 cup baking dish (Note 5). Then pour over 1/3 of the Cream Mixture, scatter with 1/3 of the salt, pepper and thyme.
Layers 2 & 3: Repeat for the 2nd and third layer.
Cover & bake: Cover with foil, and bake for 1 hour 20 minutes or until the potatoes in the middle are soft (use knife to test), it might take 1 1/2 hours. (Note 6)
Top with brie, bake again: Remove foil. Place brie on the surface, cut side down. Bake for a further 30 minutes until the brie is oozy and the edges tinged with gold.
Serve – Stand 5 minutes before serving and be prepared to swoon!
