Preheat your oven to 425°F (220°C). Line a baking sheet with parchment paper if desired for easier cleanup.
In a mixing bowl, combine the olive oil, ranch dressing mix, garlic powder, black pepper, and salt. Stir well to create a seasoning mixture.
Add the halved baby potatoes to the mixing bowl and toss them until they are evenly coated with the seasoning mixture.
Spread the seasoned potatoes in a single layer on the prepared baking sheet.
Roast the potatoes in the preheated oven for 25 minutes, turning them halfway through for even cooking.
After 25 minutes, remove the baking sheet from the oven and sprinkle the shredded cheddar cheese evenly over the potatoes.
Return the baking sheet to the oven and bake for an additional 5 minutes, or until the cheese is melted and bubbly.
Once done, remove the potatoes from the oven and allow them to cool for a couple of minutes before serving. Garnish with chopped fresh chives if desired.