Ingredients:

  • 4 large Sweet Potatoes (Yams), peeled (about 2.5 lbs or 1.2 kg)
  • 1 cup Fresh or Frozen Cranberries (120 g)
  • 1 Tbsp Unsalted Butter (for greasing)
  • 1 ½ cups Heavy Cream (Double Cream)
  • ½ cup Whole Milk
  • 2 Large Eggs, lightly beaten
  • ½ cup Dark Brown Sugar, packed
  • 1 tsp Vanilla Extract
  • 1 tsp Fresh Ginger, finely grated, or ½ tsp ground ginger
  • 1 tsp Ground Cinnamon
  • ½ tsp Freshly Grated Nutmeg
  • ¼ tsp Fine Sea Salt
  • ½ cup All-Purpose Flour (Plain Flour)
  • ½ cup Pecan Halves, roughly chopped
  • 4 Tbsp Unsalted Butter, cubed, chilled
  • ¼ cup Light Brown Sugar, packed

Instructions:

  1. Preheat oven to 375°F (190°C). Grease the 9x13 inch baking dish generously with 1 Tbsp of butter.
  2. Using a mandoline or sharp knife, slice the peeled sweet potatoes to a uniform thickness, about ⅛ inch (3 mm). Set aside.
  3. Whisk the Custard: In a large bowl, whisk together the heavy cream, whole milk, beaten eggs, dark brown sugar, vanilla extract, grated ginger, cinnamon, nutmeg, and salt until the sugar is fully dissolved.
  4. Make the Crumble: In a separate small bowl, combine the flour, chopped pecans, and light brown sugar. Add the chilled, cubed butter and use your fingertips to cut the butter into the dry ingredients until the mixture resembles coarse, pea-sized crumbs. Place the crumble mixture in the refrigerator to chill.
  5. Layer the Gratin: Arrange one-third of the sliced sweet potatoes in a slightly overlapping pattern across the bottom of the prepared dish.
  6. Sprinkle half of the cranberries evenly over the potato layer. Gently pour one-third of the spiced custard mixture over the layer, ensuring the liquid flows between the slices.
  7. Repeat with a second layer of potatoes, the remaining cranberries, and another third of the custard.
  8. Top with the remaining potatoes and pour the final amount of custard over the top. Gently press down on the layers to ensure the custard is evenly distributed.
  9. Initial Bake: Cover the dish tightly with aluminium foil. Bake for 30 minutes. This ensures the Sweet Potato Cranberry Gratin is tender before the crumble is added.
  10. Second Bake: Remove the foil. Sprinkle the chilled pecan crumble evenly over the top. Return to the oven (uncovered) and bake for an additional 20–25 minutes, or until the potatoes are fork-tender and the crumble is golden brown.
  11. Rest: Remove from the oven and let the Sweet Potato Cranberry Gratin rest on a wire rack for at least 10 minutes before serving. This allows the custard to properly set.