Potato and Squash Gratin

Potatoes and butternut squash are paired with a garlicky cream and Gruyère cheese for a dish that's worthy of going back for a second scoop. This rich, creamy side dish is perfect for a potluck dinner or party.

8 medium-sized Yukon gold potatoes, peeled
5 butternut squash necks, peeled
10 eggs
4 cups heavy cream (1 L)
10 sprigs thyme, leaves only, discard stems
4 medium-sized cloves of garlic, grated on a microplane
2½ tsp. sea salt (37.5 mL)
1½ tsp. black pepper, freshly cracked (7.5 mL)
2 cups Gruyère cheese, grated (500 mL)

Preheat an oven to 325°F (165°C/140°C fan, Gas Mark 3). Line pan with parchment paper.

Mix cream, eggs, garlic, salt and pepper with a whisk. Divide the cream mixture into two bowls.

Utilize a French or Japanese mandolin to slice potato and squash separately. The slices should be about 2 cm thick. Toss the cream to coat the squash and potato slices so the potato does not oxidize. Fold in ½ cup of cheese amongst the two bowls.

Build the gratin by alternating the layers of potato and butternut squash. Add in as much of the remaining cream as possible into the dish.

Poke several holes from the top to the bottom of layers with a small pairing knife so the cream can fill the layers. Wrap with tin foil and bake at  for 90 minutes. Check for doneness by piercing a small pairing knife right into the layers of the gratin. It should have no resistance at all.

Remove the tin foil and spread the rest of the Gruyère cheese on top of the gratin.

Increase the oven temperature to 400°F (200°C/180°C fan, Gas Mark 6).

Melt and brown the cheese for eight minutes or until desired colour is reached. Allow to set for 15 minutes out of the oven before slicing and serving.

Makes 16-20 servings.