Preheat the oven to 425 degrees and line two baking sheets with parchment.
Place potatoes on a baking sheet, drizzle with a tablespoon or two of olive oil and sprinkle generously with salt and pepper. Bake for 45 minutes or until golden, flipping halfway through.
Add the corn and 3 garlic cloves to the second baking sheet. Bake for 15-20 minutes.
Cook the bacon in a large pan over medium-low heat until crisp. Drain on paper towels. Reserve 2 T of bacon fat for the dressing.
When the corn and garlic are done, finely mince the roasted garlic. Mix in a large bowl with mayo, sour cream, lemon juice, dill, parmesan, reserved bacon fat, and cider vinegar. Taste and adjust the flavors to your preferences.
In a large bowl mix together potatoes, corn, bacon, and prepared dressing.
Garnish with chives.