Preheat oven to 425 F.
Dice potatoes in salad size pieces.
In a large bowl toss the potatoes with corn, onion, olive oil, salt & pepper.
Spread potatoes in a single layer on a cookie sheet prepped with parchment paper and non stick cooking spray.
Chop bacon and distribute evenly through potatoes.
Lightly smash garlic distribute cloves evenly through potatoes.
Roast until potatoes are cooked and crisp (about 30-35 minutes).
Combine mayonnaise, sour cream, horseradish, lemon juice, dill, Parmesan cheese and salt (keep in mind bacon will add salt and potatoes have been seasoned) and pepper to taste.
After roasting with the potatoes remove garlic cloves. Mash them into a paste and add to dressing.
Drain baking sheet of any excess grease.
Toss roasted potato mixture with the dressing. Serve warm. Leftovers are delicious cold!