Heat the Oil: In a large sauté pan or cast-iron skillet, warm the vegetable oil over medium-high heat until shimmering but not smoking. This creates the perfect foundation for achieving crispy potatoes and ensures the onions will caramelize properly without burning.

Add Potatoes and Onions: Carefully add the peeled and sliced potatoes along with the thinly sliced onions to the hot oil. Season generously with salt and pepper to taste. If desired, incorporate optional seasonings like garlic powder and red pepper flakes at this stage to infuse the flavors throughout the cooking process.

Cook to Perfection: Turn the mixture frequently with a spatula to ensure even browning, cooking for approximately 10-15 minutes until the potatoes develop a golden-brown crust and the onions become translucent and caramelized. For a softer, more tender result, cover the skillet during part of the cooking process to create steam that will help cook the potatoes through.

Drain and Garnish: Once the potatoes and onions have reached your desired level of doneness, transfer them to a platter lined with paper towels to absorb any excess oil. Sprinkle with freshly chopped chives for a burst of color and fresh flavor before serving hot.