Cook the Potatoes: Wash the potatoes thoroughly and cut larger potatoes into evenly sized pieces. Place them in a large pot and cover with cold, salted water. Bring to a boil and cook for about 10–15 minutes, or until the potatoes are fork-tender but still firm.
Drain and Cool: Drain the potatoes well in a colander. Let them cool for several minutes before combining them with the dressing so they don't become mushy.
Cook the Bacon: While the potatoes cook, place the bacon in a skillet over medium heat. Cook until crisp and golden. Transfer to a paper towel-lined plate, let cool, then crumble into small pieces.
Make the Dressing: In a small bowl, whisk together the mayonnaise, sour cream, Dijon mustard, minced garlic, salt, and black pepper until smooth and creamy.
Combine the Salad: Add the cooled potatoes to a large mixing bowl. Pour the dressing over the potatoes and gently toss until evenly coated.
Add the Toppings: Fold in most of the crispy bacon, shredded cheddar cheese, sliced green onions, and fresh parsley. Reserve a little bacon, cheddar, and green onion for garnish.
Chill: Cover the potato salad and refrigerate for at least 1 hour. Chilling allows the flavors to blend and gives the salad its best texture.
Garnish and Serve: Before serving, gently stir the salad. Sprinkle the reserved bacon, cheddar cheese, green onions, and parsley over the top. Serve chilled alongside steak, burgers, grilled chicken, or your favorite BBQ dishes.