Unroll the puff pastry sheet and make 4 disks to the size larger than the cast iron pan.
Lightly oil/butter the cast iron casserole dishes on the inner side and fill it with pav bhaji mixture to 3/4. Place the puff pastry disk on top of it and seal the edges lightly. Repeat the process for the other 3 cast iron pans.
Bake in the preheated oven for 20 - 25 min until the pastry is golden brown. Allow them to cool down for 5 minutes before garnish.
Garnish with chopped onions, coriander leaves and butter cubes. Serve hot along with lemon wedges.
If you have any left over Pav Bhaji, don't think twice. Toast some dinner rolls and serve them along..