Ingredients:
- 1 medium Japanese sweet potato (approximately 300g / 10.5 oz), peeled and cut into 1-inch pieces
- 1 tablespoon (15ml) unsalted butter, melted
- 2 cups (473ml) heavy cream
- ½ cup (120ml) whole milk
- 1 vanilla bean, split lengthwise and seeds scraped (or 1 teaspoon vanilla extract)
- 5 large egg yolks
- ⅓ cup (67g) granulated sugar
- Pinch of sea salt
- ¼ cup (50g) granulated sugar, for each ramekin before serving
Instructions:
- Toss sweet potato pieces with melted butter. Roast at 400°F (200°C) until tender (approx. 20-25 minutes). Puree until smooth using a food processor or blender. Set aside to cool slightly.
- Combine heavy cream, milk, vanilla bean (and seeds), and salt in a saucepan. Heat over medium heat until just simmering. Remove from heat and let steep for 15 minutes (remove vanilla bean shell).
- In a separate bowl, whisk together egg yolks and sugar until pale and slightly thickened.
- Gradually drizzle the warm cream mixture into the egg yolk mixture, whisking constantly to prevent curdling.
- Stir in the cooled sweet potato puree until well combined. Strain the mixture through a fine-mesh sieve (optional) for a smoother texture.
- Divide the custard mixture evenly among the ramekins.
- Place ramekins in a baking pan and fill with hot water until it reaches halfway up the sides of the ramekins. Bake at 300°F (150°C) for 40-50 minutes, or until the edges are set but the center still jiggles slightly.
- Remove from the oven and let cool completely. Cover and refrigerate for at least 2 hours (or preferably overnight) to fully set.
- Just before serving, sprinkle a thin, even layer of granulated sugar over the top of each crème brûlée.
- Use a kitchen torch to caramelize the sugar, moving it constantly to prevent burning. Alternatively, broil on low in oven (watch carefully) until caramelized.
- Let the caramelized topping cool slightly before serving (a minute or two).