For the curry, heat the Trex in a large saucepan. Add the meat a handful at a time, browning each handful before adding the next. This is really important to achieve a good flavour.
Add the onion and cook for two to three minutes, then add the garlic, ginger, pepper, carrots, tomatoes, curry paste, stock and creamed coconut. Season. Reduce the heat to low, then cover and cook for 1 hour, or until the meat is tender.
To make the dumplings, sift the flour, baking powder and salt into a bowl. Add the Trex and rub in with your fingertips until the mixture looks like fine crumbs. Stir in the cumin seeds and coriander. Add just enough chilled water to make a soft, but not sticky, dough. Draw the dough together, knead for a few moments until smooth, then form into eight even-sized balls.
Stir the curry, then put the dumplings on top. Cover and simmer for a further 15-20 minutes, until the dumplings are swollen and fluffy. Serve, garnished with extra coriander.