• Before You Start…Please note that this recipe requires 2+ hours of chilling time.

  Gather all the ingredients.
  

To Steam the Kabocha

• Quickly rinse 15 oz kabocha squash under water and remove the seeds with a spoon.
  
• Cut the kabocha into wedges and then 2-inch pieces.
  
• Fill the inner pot of an Instant Pot with 1 cup water and set a steamer basket inside.
  
• Put the kabocha in a single layer.
  
• Close the lid and set to High pressure for 2 minutes.
  
• Make sure the steam release handle points at Sealing and not Venting. The float valve goes up when pressurized.
  

To Make the Caramel Sauce

• While you’re waiting for the kabocha to finish cooking (and naturally releasing pressure for 10 minutes), make the caramel sauce. Boil water in a kettle or saucepan and set aside (you will only need 2 Tbsp hot water). Put 4 Tbsp sugar and 1 Tbsp water in a small saucepan.
  
• Gently shake the saucepan to evenly distribute sugar and do not touch until the mixture starts to turn golden brown. Gently shake the pan again to distribute the mixture to have an even color.
  
• When the caramel reaches an amber color (I like a slightly darker color, which has a mild bitterness), turn off the heat and quickly add 2 Tbsp hot water to loosen it. The caramel will splash, so use a lid to protect yourself from getting splattered with hot caramel.
  
• Swirl the saucepan to make an even mixture. Divide and pour the caramel into 4 ramekins. Allow the caramel sauce to cool.
  

To Make the Kabocha Purée

• When it’s finished cooking, the Instant Pot will switch automatically to the Keep Warm mode. Let the pressure release naturally for 10 minutes  (DO NOT EXCEED 10 minutes; I recommend setting a timer.) and then proceed with quick release by turning the steam release handle to the Venting position to let the steam out until the float valve drops down. Hold a kitchen towel over the release valve and do not place your hand or face over it. Only a little bit of steam will be left after 10 minutes of natural release.
  
• Open the lid and remove the steam rack from the Instant Pot.
  
• Use a knife or spoon to remove the kabocha‘s flesh. Discard the kabocha skin (it’s edible, but we do not use it in this recipe).
  
• Now, make a kabocha purée with a flour sifter, fine-mesh sieve (uragoshiki in Japanese), or a food processor. Set the sieve over a sheet of parchment paper and press the steamed kabocha through the mesh with a wooden spatula. Once it’s all done, flip the mesh sieve and take out the puréed kabocha onto the parchment paper. If you’re using a food processor, process the kabocha into a purée.
  
• Measure ½ cup (120 g) kabocha purée from the pile. Tip: With almost 1 lb kabocha, you will have enough to make 4 ramekins, but you may not have enough purée for another batch. It’s hard to predict the real weight of kabocha with the seeds included, so please adjust accordingly. You can save the purée for up to 3 days in the refrigerator. I sometimes make Kabocha Soup with the leftover purée.
  

To Make the Custard Mixture

• In a large bowl, combine 3 large eggs (50 g each w/o shell) and 3 Tbsp sugar and whisk well.
  
• Add ½ cup milk, ½ cup heavy (whipping) cream, and 1 tsp pure vanilla extract. Whisk to combine.
  
• Add the kabocha purée and mix until thoroughly combined.
  
• For the best texture, set a fine-mesh sieve over a large bowl (I use a 4-cup liquid measuring cup) and pass the custard mixture through the sieve. If you have a smaller fine-mesh strainer, you can directly pour the custard mixture over the ramekins.
  
• Divide the custard mixture into 4 ramekins.
  
• Cover each ramekin tightly with a sheet of aluminum foil.
  

To Pressure Cook

• Add 1 cup water into the Instant Pot and place the steam rack inside.
  
• Put the 4 ramekins on the rack and make sure they are not tilted.
  
• Close the lid and set to High pressure for 6 minutes. Make sure the steam release handle points at Sealing and not Venting.
  
• When it’s finished cooking, the Instant Pot will switch automatically to the Keep Warm mode. Let the pressure release naturally for 10 minutes (DO NOT EXCEED; I recommend setting a timer.) Then, proceed with quick release by turning the steam release handle to the Venting position to let the steam out until the float valve drops down. Hold a kitchen towel over the release valve and do not place your hand or face over it. Only a little bit of steam will be left after 10 minutes of natural release.
  
• Take out one ramekin and remove the aluminum foil. Insert a skewer in the center of the flan to see if the custard is set and no liquid comes out. If it’s not cooked through, repeat the pressure cooking process (the cooking time varies depending on your result).
  
• Remove the ramekins to the counter and let cool until the flan is room temperature. Then, put the ramekins on a tray, cover with a paper towel (to absorb any condensation/moisture) and plastic, and transfer to the refrigerator to chill for at least 2 hours or preferably overnight.
  

To Serve

• Run a knife around the edges of the ramekins.
  
• Hold a ramekin and plate together and shake vigorously a few times to invert the flan onto the plate. Enjoy!
  

To Store

• You can store the leftovers in the refrigerator for up to 2 days.