How to Make It
In a medium saucepan, heat the vegetable oil. Add the sliced onions and cook them over high heat, stirring occasionally, until they are golden brown, about 10 minutes. Transfer half of the onions to a plate.
Add the peppercorns, cardamom, cloves, chiles and cinnamon stick to the onions in the saucepan and cook over moderately high heat for 1 minute, stirring. Stir in the rice, lentils, water and 2 teaspoons of salt and bring to a boil. Reduce the heat to moderately low, cover and simmer for 15 minutes, until the water is absorbed and the rice and lentils are tender.
Meanwhile, in a medium bowl, toss the sliced cucumber with the yogurt, jalapeños and garlic and season with salt and pepper.
Gently fluff the rice and lentils with a fork and discard the whole spices. Transfer the rice to a platter, garnish with the reserved onions and serve with the cucumber raita.