In a large pot over medium, heat the oil until shimmering. Add the shallots and ginger, then cook, stirring occasionally, until the shallots are translucent, 2 to 3 minutes. Add the cumin and turmeric, then cook, stirring, until fragrant, about 30 seconds. Stir in the chili, cilantro stems and pasta. Add 3 cups water, 1 teaspoon salt and ½ teaspoon pepper, then bring to a simmer over medium-high. Cover, reduce to medium-low and cook, stirring occasionally, until the pasta is al dente.