Preheat the oven to 350 degrees Fahrenheit.
Cut the head of cauliflower into small bite-sized florets and place on a baking sheet. Drizzle the cauliflower with olive oil and bake in the oven for 20 minutes until the cauliflower is tender and slightly golden.
While the cauliflower is baking, fry the bacon in a pan on the stove. Once it's crisp, roughly chop it into small bite-sized pieces.
In a food processor or using a hand blender, combine the mayonnaise, pickles, Dijon mustard, vinegar, salt, and pepper and blend until the pickles are broken into small pieces. Taste and adjust the seasoning as needed.
Once the cauliflower is tender, remove from the oven and allow to cool before transferring to a salad bowl. Top with the chopped bacon, red onion, celery, parsley, and chives. Pour the dressing over top and toss until well coated. Enjoy!