Bring water, lentils, ginger and salt to a boil in a medium saucepan. Reduce heat to medium; simmer uncovered until lentils are tender, about 10 minutes – be sure not to overcook the lentils, you’ll want them to have some texture.
Meanwhile, heat oil in medium skillet over medium heat. Add onions and sauté until they soften and brown, about 5 minutes. Mix in chili powder, curry powder and walnuts; stir 1 minute then remove from heat and set aside.
Stir onion mixture and cilantro into lentils. Transfer to bowl. Sprinkle with additional cilantro before serving, if desired.