Fill a large Dutch oven (casserole) or other ovenproof pot with water and a generous pinch of salt and bring to a boil over medium-high heat. Add the rice and cook, stirring occasionally, until just past halfway tender, 5–7 minutes. Drain and let cool slightly.

Preheat the oven to 375°F (°190C/Gas Mark 5). Grease the Dutch oven with 1 tablespoon oil. Return the drained rice to the Dutch oven along with the lamb, cilantro (coriander), and scallions (spring onions). In a medium bowl, whisk together ⅓ cup (75 ml/2½ fl oz) water, the ½ cup (120 ml/4 fl oz) oil, salt, and pepper, then pour over the rice mixure and mix thoroughly. Cover the Dutch oven and bake until the rice is fully tender and the meat is cooked, about 1 hour.

Remove from oven and let stand for 10 minutes before uncovering. Serve hot.