In a large saucepan, heat the olive oil over medium heat. Add the shallot, ginger, curry powder and turmeric and cook, stirring until the spices are fragrant, about 1 minute.
Add the lentils, stock and coconut milk. Raise the heat to medium-high and bring to a boil. Reduce the heat to low, cover partially, and simmer until the lentils are tender but still firm, about 12 minutes. The mixture should be brothy; add a little water if needed.
While the lentils simmer, toast the sesame seeds. Place the sesame seeds in a small, dry saute pan over medium heat. Cook briefly, shaking the pan often and watching carefully to prevent burning. Remove the seeds from the pan as soon as they begin to turn brown. Set aside.
Stir the spinach into the lentils, cover and simmer for about 3 minutes longer. The lentils should still hold their shape.
Uncover and stir in the salt. Garnish with the cilantro and toasted sesame seeds.