Step 2
While the egg noodles cook, heat mustard oil in a saucepan over medium-high heat. Add onion and fry until light brown, about 5 minutes. Add chiles, garlic, ginger, lemongrass, cumin, and turmeric; sauté for 1 minute. Add bell pepper and mushrooms; stir-fry for 6 minutes. Add broth, tomatoes, yogurt, soy sauce, ajwain, bay leaf, salt, and pepper; cook until vegetables are tender, about 5 minutes.