Japanese Sweet Potato (Dessert)

Instructions

1. Gather all the ingredients. Preheat the oven to 375ºF (190ºC). For a convection oven, reduce cooking temperature by 25ºF (15ºC).
2. Wash 3 Japanese sweet potatoes carefully (the skin is edible and very nutritious) under running water. Pat dry with a paper towel.
3. Wrap each sweet potato with a sheet of aluminum foil. Poke a few holes in the potatoes with a skewer (for steam to escape).
4. Put the sweet potatoes in the oven and bake for 50–60 minutes, or until the inserted skewer goes through all the way.
5. Carefully open the aluminum foil and cut the sweet potato in half lengthwise. Make sure not to tear the skin.
6. While it's hot, scoop out the flesh with a spoon, leaving a ¼-inch (5-mm) wall around the edges to create a shell. We use the shells to stuff the sweet potato puree later on, so be careful not to break the wall. You will only use the 5 best-looking shells out of 6.
7. Transfer the sweet potato flesh onto a fine-mesh sieve and strain the flesh by pressing it with a wooden spatula. Alternatively, you can put the flesh in a food processor and make a puree (you may need to add a tiny bit of water if the sweet potato flesh is too dense).
8. Continue with the rest of the sweet potatoes. Collect the strained pureed sweet potato in a bowl.
9. In a medium saucepan, heat 2 Tbsp unsalted butter over medium-low heat. Once the butter is completely melted, add the pureed sweet potato.
10. Add 5 Tbsp sugar and mix well together.
11. Then, add 2 large egg yolks one at a time and quickly incorporate into the sweet potato mixture so the egg doesn't become cooked and scrambled. Keep stirring.
12. Gradually add ⅓ cup heavy (whipping) cream, stirring continuously, and combine well with the mixture.
13. Add ½ tsp pure vanilla extract and mix until the mixture is smooth and creamy. If the mixture turns into a big lump and not the silky texture, you can add more melted butter and/or heavy cream to loosen up. Turn off the heat.
14. Scoop the mixture into the sweet potato shells. I use a cookie dough scooper to make the job easier (this is great for portion control, too).
15. Using an offset spatula (or a silicone spatula), smooth out the surface of the filling, creating a gentle slope in the center of the sweet potatoes.
16. Place the sweet potato shells on a baking sheet lined with a sheet of parchment paper.
17. In a small bowl, whisk 1 large egg yolk and brush the egg wash on the sweet potato mixture.
18. Sprinkle ½ tsp toasted black sesame seeds on the center of each sweet potato.
19. Position the rack in the middle of the oven. Broil on Medium (500ºF/250ºC) for 3–4 minutes, or until the top starts to brown a little bit.
20. Remove from the oven and serve immediately.