Heat the oil in a saucepan, add the cumin seeds, garlic and ginger and cook over a medium heat, stirring, for 1 minute.
Add the lentils and cook for a further minute.
Add the stock, a large ladleful at a time, and cook until each addition has been absorbed before adding the next. Continue in this way until all the stock has been absorbed. This should take about 20–30 minutes. Remove from the heat and stir in the mint and coriander with a squeeze of lime juice.
To serve, divide the spinach leaves between individual bowls, top with a quarter of the lentils and the goats' cheese and sprinkle with pepper.