01 - Heat the vegetable oil in a large skillet over medium heat until it shimmers slightly.
02 - Add the chopped onion to the skillet and sauté for 3-4 minutes, stirring frequently, until softened and translucent.
03 - Stir in the minced garlic, chopped chiles, and tomatoes if using. Cook for another 2-3 minutes until fragrant and the chiles begin to soften.
04 - Add the diced potatoes, ground cumin, smoked paprika if using, salt, and pepper. Toss everything together to evenly coat the potatoes in the spice mixture.
05 - Pour in the vegetable broth or water, stir gently, then cover the skillet with a lid. Cook for 20-25 minutes, stirring occasionally, until the potatoes are fork-tender and the liquid is mostly absorbed.
06 - Remove the lid and taste the dish. Adjust salt and pepper as needed, allowing any remaining liquid to cook off for 1-2 minutes if desired.
07 - Transfer to a serving dish and garnish generously with fresh chopped cilantro. Serve warm as a side or main course.