Recipe Detail Page

1. Rub butter over bottom and sides of a 9 x 13-inch (23 x 33-cm) foil baking dish (with no holes). Peel potatoes, working quickly so they don’t brown. Using a very sharp knife, thinly slice potatoes so that pieces are no thicker than 1/4 inch (5 mm). This helps the potatoes bake faster. Or, for easier slicing, use a mandoline or food processor to slice potatoes. Even though these cuts can be done with a knife, using a mandoline is quicker and more precise. Always use the safety guard to hold the potato in place, then slide it back and forth over the blade.

2. Pour whipping cream and broth into a large pot. Stir in garlic, bay leaf, nutmeg and salt, then add potatoes, separating slices as you add them. Bring to a boil, covered, over medium-high heat. Uncover. Simmer gently, stirring occasionally, until potatoes are almost fork-tender, 10 to 13 minutes. Discard bay leaf. Turn potato mixture into baking dish. Press so potatoes are completely submerged.

3. Scatter onion and cheese overtop. Cover tightly with foil. If making ahead, let cool then tuck in the fridge up to 1 day. Bring to room temperature before proceeding with next step.

4. Preheat one side of barbecue to medium or medium-low so the temperature is 325°F (163°C).

5. When ready, place baking dish over hot side of grill and cook, covered, until hot, 15 to 20 minutes. Uncover and continue baking until cheese melts, mixture is bubbling and edges are golden. Remove from heat. Re-cover and let stand at least 15 minutes. Serve topped with thyme.