Dry roast halved walnuts and shelled and whole pistachios separately until fragrant.
Take them off the heat, and cool. Chop very very finely. You can also use a food processor, just ensure that they don't turn into a powder.
Carefully place one sheet of phyllo in the pan. Add another one on top. Let the pastry hang over the edges of the pan.
Brush liberally with the butter. Sprinkle a fourth of the chopped nuts evenly on top.
Cover the nuts with 2 sheets of phyllo. Brush with butter. Sprinkle another fourth of the nuts on top. Repeat this process 2 more times.
Cover the nuts with the remaining 2 sheets of phyllo.
Pour the cheesecake filling into this prepared crust.
Trim the overhanging pastry sheets with a pair of scissors. Leave about 1"- 2" of the crust.
Bake in the preheated oven for 60-75 minutes at 325F, or until the cake is golden and has the slightest of the wobble n the center. My cake took 75 minutes.
Switch off the oven and leave the cake in the oven for 15-20 with the oven door slightly ajar.