Grilled Garlicky Smoked Gouda Potato Gratin

A riff on scalloped potatoes, this version with loads of garlic and gooey cheese is definitely amped up, taking the whole thing into gratin territory. It makes the perfect buddy for grilling alongside a barbecued main. Or, if you aren’t barbecuing, simply finish baking it in the oven at the same temperature. 
Ingredients:
1 tablespoon butter for greasing
6 medium-size russet or Yukon Gold potatoes
1 1/2 cups (375 mL) whipping cream (35%)
1 cup (250 mL) chicken broth
8 roasted garlic cloves or 4 fresh garlic cloves, grated
1 bay leaf
1/2 tsp (2 mL) freshly ground nutmeg
1/2 tsp (2 mL) salt
1 small cooking or red onion, cut into rings
1 1/2 cups (375 mL) grated smoked Gouda, about 170 g
1 tbsp (15 mL) fresh thyme leaves (optional)

Directions:

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.

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.

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.

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

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. Makes 8 to 10 side-dish servings.