Bring a saucepan of water to a boil. Add potatoes; reduce heat to medium. Cook until tender, 15 to 20 minutes.
Heat oil in a skillet over medium heat. Add mustard, cumin, and coriander seeds. Cook, stirring constantly, until lightly browned, about 1 minute. Stir in sesame seeds; cook until golden brown, 1 to 2 minutes. Add potatoes, lemon juice, lemon zest, chile peppers, and turmeric. Stir until well combined. Season with salt and pepper.