Rice and lentils with caramelised onion

Method

1. Rinse the lentils and cook them in 1 L of unsalted water over medium heat for 12 to 15 minutes, until tender but still firm. Drain, keeping the cooking water.
2. While the lentils cook, slice the onions into thin half-moons. In a wide frying pan over medium heat, warm 60 ml of the olive oil, add the onion and a pinch of salt and cook for 25 to 30 minutes, stirring now and then and lowering the heat if it starts to catch, until dark brown and soft.
3. In a medium pan over medium heat, warm the rest of the olive oil and fry the chopped garlic and cumin for 30 seconds. Add the rice and stir for 1 minute to coat the grains.
4. Measure 600 ml of the lentil water (top up with boiling water if short), bring it to the boil and pour it over the rice with the lentils, 1½ teaspoons of salt and the pepper. Stir once, cook uncovered until the liquid drops to the level of the rice (about 7 minutes), then cover, turn the heat to the lowest and cook 10 minutes. Turn off and rest covered for 5 minutes.
5. Chop the mint and stir it into the yogurt with a pinch of salt.
6. Fork half the onions through the rice and serve with the rest of the onions on top and the yogurt alongside.