How to Make It
Slice the onion crosswise into 1/2-inch-thick rings. Brush onion rings evenly with olive oil. Grill the slices on unoiled grates over medium-high heat (400°F to 450°F) until grill marks appear, about 5 minutes per side.
Remove from grill. Cool 10 minutes, and chop.
Stir together chopped onion, sour cream, grated Parmesan cheese, kosher salt, black pepper, and hot sauce in a bowl. Sprinkle with chopped chives. Serve with chips.