Preheat oven to 350 degrees.
Melt 3 Tablespoons butter in a large saucepan over medium heat. Add the diced onions and cook for 4 minutes. Add the garlic and cook for 1 additional minute.
Add the remaining 5 tablespoons butter until melted. Remove from heat.
Stir in cream of chicken soup, sour cream, salt/pepper, hot sauce. Set aside ½ cup of cheese and add the rest to the saucepan mixture.
Use a silicone spatula to stir in the potatoes until well-combined.
Transfer to a lightly greased 9 x 13 baking dish. Top with remaining ½ cup cheese.
Combine the melted butter, potato chips, and Parmesan cheese. Spread evenly over the potatoes.
Bake, uncovered, for 40 minutes. Let it sit for 5 minutes prior to serving. Garnish with chives if desired.
