Peel and mince 2 cloves garlic. In a small saucepan, heat garlic, ¾ cup cream, ½ cup milk, 30 g butter, ½ tsp salt, and ¼ tsp black pepper until warm (do not boil).
Layer stacks
Peel and thinly slice 600 g potatoes (2–3 mm thick) using a mandoline or sharp knife. Grate 100 g Gruyère or cheddar cheese. In a mixing bowl, toss sliced potatoes with the cream mixture until evenly coated. Lightly spray a muffin tin or ramekins with oil spray. Layer potato slices into each hole, pressing down gently. Sprinkle with Gruyère or cheese between layers.
Steam cook
Place muffin tin on a rack in the preheated Combi Steam oven and cook for 25 minutes, until potatoes are tender. Remove from oven.
Crisp finish
Change oven setting to fan bake and preheat to 220 °C with medium steam or 50%. Sprinkle tops with 40 g Parmesan cheese. Return the tin to the preheated oven and bake for 10–15 minutes, or until golden and crisp.
Serve
Allow stacks to cool slightly, then run a knife around edges to loosen. Serve warm as a side dish to roasts, poultry, or fish.
Notes
Potatoes can be made ahead to the steaming stage, cooled, then crisped just before serving.