Add shallots to pot; sauté until golden, about 6 minutes. Add cinnamon sticks, ginger, cumin, turmeric, and cayenne. Stir until fragrant, about 1 minute. Increase heat to high; add broth and 3 tablespoons lemon juice. Bring to boil; reduce heat to low, cover, and simmer until shallots begin to soften, about 18 minutes.