Gather ingredients and tools.
Using 1-2 Meyer Lemons, lightly scrape the zest. You want to get just the yellow part of the zest. The white pith is bitter, so try not to get any of that. You will need about 1 Tbsp of the zest.
Using fresh Meyer Lemons, slice in half and juice 2-3 lemons until you have 1/2 cup of juice.
In a glass bowl that will fit in your Instant Pot, add egg yolks, sugar, and lemon juice.
Whisk until well combined and smooth.
Add lemon zest and stir to combine.
Cover the bowl with the silicone lid, making sure it is tight. Place on Silicone trivet with handles.
Put 1 cup of water in your instant pot and lower the bowl into the pot.Cook on manual, high pressure for 5 minutes. Then leave in the pot for a full 10 minutes. (Note, the pin will drop before the time is up, that's fine. Just leave it in the pot, closed for the full 10 minutes.
Lift the trivet from the pot, and carefully open the silicone lid. It will look a little speckled on top.
Use your silicone whisk and stir the curd to mix well.
You will be able to see if the curd is thickening by testing on the back of a spoon.
The curd may appear thin. That's okay, it will thicken as it cools. Tip: If you are making your curd ahead of time, you can put it into a mason jar (or two if you have doubled the recipe like I usually do!) Let it cool completely, then cover and put in the refrigerator until you are ready to use it. When you take it out of the fridge, give it a stir before adding it to your cream base.
The curd must be completely cooled before you can combine it to make the semifreddo. A quick way to cool it is to take a larger bowl and fill it with some ice, and set your curd bowl in it.
Using a silicone scraper, stir and scrape around the bowl occasionally as the mixture cools. While the curd is cooling you can begin with the cream base.