Preheat your oven to 400 degrees Fahrenheit (200 C). Peel and chop your potatoes, first in half lengthways then into half moons shapes
Parboil them in a pan of salted boiling water for around 10 minutes
Next, over a low heat, heat up 5tbsp of oil (you’ll want this oil to cover the base of a baking tray so adjust quantities accordingly). Grab your garlic cloves (skin on) and rosemary sprigs and place them into the pan to infuse the oil. After a couple minutes drain the oil into a deep baking tray, keeping the rosemary and garlic. Place the baking tray in the oven
Drain your potatoes, and rough them up by tossing in a colander or shaking in a pan, leave for around 10 minutes to ensure they are dry. Then place into the baking tray of oil and put pack in the oven for 30-45 minutes at 400 degrees Fahrenheit (200 C) (keeping an eye on them for a golden brown finish)
Peel your garlic out of their skins, and remove the rosemary leaves from their stalks. Mash them both together using the back of a fork to form a paste
Finally, remove the potatoes from the oven when they’re golden and crispy around the edges. Season with a generous pinch of sea salt flakes, and top with the rosemary and garlic paste. Toss together and serve!