Hearty Sweet Potato Au Gratin

This versatile side dish will go well with pretty much everything, from sausages to your favourite roast.


  • oven
  • peeler
  • medium saucepan
  • whisk
  • 8 x 8-inch (20 x 20 cm) baking dish
  • foil


  • 2 medium sweet potatoes, about 1 1/2 lb (750 g) in total
  • 2 Tbsp (30 mL) butter
  • 1 large clove garlic, minced
  • 1/2 Tsp (2 mL) salt
  • 2 Tbsp (30 mL) all-purpose flour
  • 2 cups (500 mL) 18% cream or a 473 mL container
  • 2 Tbsp (30 mL) chopped fresh thyme (optional)
  • 1/2 cup (125 mL) shredded aged cheddar


Preheat oven to 375°F (190°C). 

Peel potatoes; slice into rounds no thicker than 1/8 inch (0.3 cm).

In a medium saucepan, melt butter over medium heat; add garlic and salt. Stir 1 minute.

Whisk in flour until combined. Gradually add cream, whisking until combined. Bring to a boil, whisking occasionally until thickened, for 2 to 3 minutes. 

Layer half the potatoes in an 8 x 8-inch (20 x 20 cm) baking dish. Scatter with half the thyme. Top with half the cream sauce. Repeat with remaining potatoes; drizzle remaining cream mixture over top. Press potatoes to even out layers and coat in cream. Cover with foil. Bake for 30 minutes.

Sprinkle with Cheddar cheese and remaining thyme. Bake uncovered for 15 minutes until bubbly and top is a deep golden brown. Let stand for 10 minutes.