Bombay Potatoes (Spicy Indian Roast Potatoes)

Name: Bombay Potatoes (Spicy Indian Roast Potatoes)
Prep time: 15 min
Cook time: 25 min
Total time: 40 min
Cuisine: Indian
Ingredients: 1 teaspoon ground turmeric (for the boiling water); 6 medium Yukon Gold potatoes (about 2 lbs, unpeeled); 2 tablespoons neutral oil (such as avocado or vegetable); 1 teaspoon black mustard seeds; 1½ teaspoons cumin seeds; ¼ cup chickpea flour (besan); 1 teaspoon ground turmeric; 2 teaspoons kosher salt; 1½ teaspoons Kashmiri chili powder (or ½ teaspoon cayenne plus 1 teaspoon paprika); 4 teaspoons water; 8 to 10 fresh curry leaves (optional); 2 tablespoons fresh cilantro (chopped (optional))