In a large pot or Dutch oven, heat the vegetable oil over medium heat. Once the oil is hot, add the chopped onions. Sauté for about 5-7 minutes until the onions become translucent and fragrant.
Stir in the curry powder and cook for an additional 1-2 minutes. This will allow the spices to bloom and infuse the oil, enhancing the overall flavor of the dish.
Add the uncooked red lentils and long-grain white rice to the pot. Stir well to combine all the ingredients.
Carefully add the vegetable stock to the pot and stir everything together. Bring the mixture to a boil.
Once boiling, reduce the heat to low and cover the pot. Let it simmer for about 20 minutes, or until the lentils and rice are tender and the liquid is absorbed.
After cooking, remove the pot from the heat. Season with salt and pepper to taste. If desired, fluff the rice and lentils with a fork. Serve hot, garnished with chopped parsley or cilantro for a fresh touch.