Preheat oven to 200c.
Place the potatoes into a large pot of water and boil until they are fork-tender (from 16 - 20 minutes depending on their size).
500 g baby potatoes
Drain the potatoes and place them on a baking sheet, spacing them out evenly.
Use tongs to hold them while you cut a cross into the centre of each potato (don't cut all the way through).
Combine the butter and spices then set aside.
30 g salted butter, ½ teaspoon sweet paprika, ½ teaspoon onion powder, ½ teaspoon garlic powder, ½ teaspoon dried rosemary, ¼ teaspoon cooking salt
Flip the potatoes over and crush them with a potato masher (see my notes).
Brush the potatoes with ⅔ of the butter mixture then bake for 40 minutes.
Remove the potatoes from the oven and flip them over (as best you can), breaking up any larger pieces as you go.
Brush potatoes with the remaining butter mixture (see my notes) and bake for a further 20 minutes or until golden brown and crispy.
Meanwhile, combine the dressing ingredients.
¼ cup sour cream, 1 tablespoon mayonnaise, 1½ teaspoon Dijon mustard, 2 teaspoon fresh lemon juice, ¼ teaspoon cooking salt, 6 shallots (green/spring onions), ⅓ cup fresh parsley (firmly packed), 2 tablespoon finely chopped fresh chives
Combine dressing and potatoes in a bowl, mixing lightly to incorporate and serve immediately.