Put the dried red chillies in a bowl with the peppercorns and coriander seeds and add 350 ml water. Soak for at least an hour.
Slice the lemongrass crossways very finely, starting at the root end and going up about 6 inches.
Put the soaking ingredients and their soaking liquid into a blender with the lemongrass, galangal, ginger and turmeric and blend well to make a paste.
Heat the oil in pan over a medium heat and when hot add the shallots and garlic. Stir and fry until golden, then add the paste from the blender and fry for about 10 minutes until the oil has seerated and the paste turned dark.
Stir the coconut milk and add to the pan with the tamarind paste, salt and sugar. Mix well and taste, then bring to a simmer, stirring. As soon as the sauce begins to bubble turn off the heat.
Strain the sauce through a sieve, pushing through as much liquid as possible. Return to the pan and add the hardboiled eggs. ( The recipe up to this far can be prepared a day in advance if wished).
Wash the fresh red chillies and the mint sprigs. Remove coarse stems from the mint.
Just before serving bring the curry back to the boil and add the tomatoes, stirring a few times and returning briefly to a simmer before tipping into a serving bowl.
Garnish with the fresh chillies and the mint sprigs and serve withrice or bread.