To make the curry spice blend, add the rice to a skillet and toast on medium heat for about 3 minutes. Add the coriander seeds, cumin seeds, peppercorns, cardamom seeds, cloves, mustard seeds, fennel seeds, and dried chiles. Toast in the pan for about 3 minutes. Set aside to cool for 10 minutes, then put in a spice grinder and grind into a powder.
Add the oil to a medium pot and bring the heat to medium. Drop in the onion and chopped Serrano pepper. Cook and stir for 5 minutes.
Add the ground curry spice mixture and turmeric. Stir to coat the onions and peppers.
Core and cut the apples into chunks. Leave the skin on and discard the cores.
Add the cut apples to the pot along with the minced garlic, sugar, and salt. Cook on medium heat for 10 minutes, then add ⅓ cup water and the coconut milk. Lower the heat to low and cook for 20 minutes.
The curry is ready to serve. Top with chopped chives or cilantro if desired.