To begin, boil your water and add in your potatoes with salt. Boil until fork tender. Preheat your oven to 400 degrees.
Toss your cooked potatoes with olive oil, gochugaru as well as salt and pepper. Mix well.
Add your seasoned potatoes to a baking sheet with parchment. Take a cup and smash down your potatoes. Repeat until you go through all your potatoes. Pour over any remaining seasoning from the bowl as well.
Transfer to the oven for about 30 minutes, flipping halfway.
In the meantime, make your mayo, mix together gochujang, mayo, rice wine vinegar, pinch of sugar, salt and pepper. Mix until combined.
When your smashed potatoes are finished, garnish with chopped parsley, lemon juice, and grated parmesan. Serve with your gochujang spicy mayo and enjoy!