Before you begin making the cheesecake filling, keep out all your refrigerated ingredients and let them come to room temperature.
Peel and slice the mangoes and blend them to a smooth puree (alternatively, use store-bought mango pulp/puree).
In a small bowl, whisk together the corn flour, sugar, salt and cardamom powder (if using).
Use a hand-help mixer or a stand mixer to beat the cream cheese until smooth and fluffy.
Add the corn starch mixture along with the mango pulp. Mix on the lowest speed until just combined. Then add the eggs one by one, beating after each addition. Ensure that you do not overmix, else the cheesecake can crack.
You can line the springform pan with parchment paper before pouring in the filling. Once the filling is ready, pour it into the springform pan. Give the pan a few raps on the counter to remove any trapped air bubbles.
In the Instant Pot, add 1.5 cups water and place the trivet stand. Place the springform pan on the trivet and cover loosely with a piece of foil.
Pressure Cook on High for 30 minutes, let the pressure release naturally. Once you open the lid of teh IP, there can be water collected on the surface of the cheesecake, This is ok - just dab it with kitchen paper.
Set the cheesecake in the fridge for at least 3 hours before serving. Before serving, decorate it with thinly sliced fresh mango pieces.