1. At least 12 hours before, submerge beans in water. When ready to use, drain water.
2. Heat a large pot over medium high heat. Add oil. Sear marrow on both sides until golden. Remove from pot and set aside.
3. Add onion to the pot. Sauté until edge start to brown. Add garlic and sauté until fragrant. Add tomato paste to the pot and caramelize it with the onion and garlic. Season it with paprika and black pepper.
4. Return marrow to pot. Add tomato sauce, broth, salt, and lemon juice. Adjust salt level to your liking.
5. Bring everything to a boil. Add navy beans and cilantro. Lower heat to a simmer and cover the pot. Simmer for two hours before serving.