For potatoes: Preheat oven to 450 degrees. Cover potatoes by at least an inch with cold water, add a pinch of salt, bring to a boil and cook until tender enough to be pierced through with a knife but not falling apart, about 10 min. Drain, transfer to a bowl and toss with 1 Tbsp. olive oil and 1 Tbsp. seasoning. Place potatoes in a greased baking pan and gently smash each with a potato masher so they flatten but stay in one piece. Sprinkle smashed potatoes with remaining 1 Tbsp. oil and seasoning. Roast for 15 min. or until browned and starting to crisp. Serve immediately garnished with sauce, slaw and toppings.
For sauce: Combine all ingredients and refrigerate until ready to use. Top potatoes with dollops of sauce or use as a dip.
For slaw & toppings: Combine carrots, celery and parsley with lime juice. Sprinkle across potatoes with blue cheese and bacon, if using.