On the evening prior, rinse and soak the split peas in a large bowl of water.
On the day of the recipe, rinse and drain the split peas. Bring the broth to a boil in a large pot and add the split peas. Simmer for 20 minutes, covered.
In the meantime, melt the butter in a frying pan and cook the onions over medium heat until translucent, about 5 minutes. Stir in the turmeric constantly into the onions over low heat for 1 minute.
Stir in the rice flour into half a cup of cold water, mix in this mixture to the onions, and pour everything immediately into the broth.
Zeste 2 tangerines, and the juice all four. Add them to the soup with the spinach, parsley, and half of the cilantro. Cook for 20 minutes over low heat, stirring occasionally.
When ready, divide amongst 8 bowls, add a big dollop of yogurt in the middle and sprinkle with the remaining cilantro.