Make a dry caramel by heating up a stainless steel small saucepan over medium heat. When the saucepan is hot, slowly sprinkle the sugar over the pan. When the sugar crystals melt, add more slowly until all of the sugar is dissolved and turned into caramel. When the caramel begins to turn into a golden amber color, remove from the heat. The caramel will continue to turn darker. Pour the caramel into the ramekins making sure you distribute it evenly.

Whisk the eggs together in a bowl. Meanwhile in another saucepan, heat up the half and half, sugar, vanilla extract, and lemon peel until it comes to a low boil. Remove the lemon peel. Temper the eggs by slowly pouring the mixture into the eggs while whisking everything together. Continue to pour the mixture until everything is combined well. Do not pour the mixture all at once or too quickly because you will risk the eggs to curdle. Strain the custard mixture into another bowl or pitcher.

Pour the custard into the ramekins with the set caramel. Make sure you distribute the custard evenly and fill below the rim. Cover the ramekins tightly with aluminum foil.

Pour 1 cup of cold water into the Instant Pot followed by a steamer rack. Then place the ramekins into the Instant Pot. (If you do not have enough space, you will have to do the cooking process twice - use fresh cold water). Cook the flan at High Pressure for 9 minutes with Natural Release. When the flan is finished cooking, carefully remove the flan and chill in the fridge for 3 - 4 hours.

When you are ready to serve, use a spatula or knife and run it along the ramekin to remove the flan. Flip the flan over in your desired serving dish and enjoy!