Wearing plastic gloves, peel and grate the turmeric.
Peel and grate the ginger.
Wearing plastic gloves, deseed and soak the chillies in a little warm water.
Place the onion, garlic, coriander roots, turmeric and ginger in a heavy-based pot or wok over a medium heat. Stir until coloured and soft. If the ingredients are taking on too much colour, add a little water to slow down the cooking process. We want the ingredients to caramelise to give the finished curry depth and added flavour.
When the ingredients are soft, scrape into a large bowl and add the drained chillies.
Set aside to cool, then blend in the blender for 3-4 minutes to a smooth reddish-yellow paste. If the paste is not wet enough, add a little water to help move the blades.
Make the spice mix
Wet the coriander, cumin and fennel seeds separately, then drain. Dry roast each, separately, (they take different times to roast) over medium heat. Cool, combine with the peppercorns and salt and grind in the mortar and pestle.
Stir the spices into the paste, mix well and place in an airtight container or jar. This paste keeps in the refrigerator or 4-6 days or you can freeze it.