beachbum,
I use it in my pre-cook of veg/potato as well as rice. You can treat like any whole spice, roasting and grinding but I use while. Simply fry in oil with your Garlic & Ginger and continue your recipe.
Out of interest, I have found 3 different variations of Panch Phoran on the internet . Two are variations of each other, mine has small yellow mustard seeds and aniseed in place of fennel. The one on its own has Radhuni in it. You can get the spice in a local Indian store.