Firstly pre-heat your oven to 200C (390F) and then peel and chop your potatoes
Now place the potatoes into a large pot of water with 4 sprigs of rosemary and a few pinches of salt and bring to a boil
Par boil the potatoes for 12 minutes (see top tips in the notes below to find out how to know when they are ready)
Now pour 2-3 tbsp of olive oil into a large baking dish/tray and place in the oven to get very hot ready for the potatoes
Drain the potatoes, removing just the rosemary stems (keep as many of the leaves as possible)and place the potatoes back into the pot you boiled them in, place the lid on and give them a couple firm shakes. This helps to break them up and to get nice and crunchy
Remove the baking dish from the oven, place the potatoes inside (you should hear them sizzling from the hot oil)
Drizzle over a good few glugs of olive oil across the potatoes making sure each is covered evenly, along with a good few pinches of salt and place in the oven for 45 minutes
Remove from the oven, turn the potatoes so they cook evenly and place back in the oven for 45 minutes or until they're golden and crispy
Don't over boil the potatoes. A trick I use to test is poke with a sharp knife. You want there to be a little restriction whilst going through the potato. If the knife slides through too easily they're over boiled and if you can slide the knife through they aren't ready.
Make sure the oil in the baking dish is nice and hot. This means it will sizzle when you add the potatoes and helps with them to go crispy.
Ideally you want to give the potatoes space to roast, this actually speeds up the process. BUT we all know the oven gets totally rammed on big days like Christmas so you can roast them like I have in the photos. They will still go crispy and taste great.
Try to cut them into equal sized pieces so they roast evenly in the oven.
Don't be tempted to skip roughing up the potatoes. This is the secret to crunchy potatoes as this step creates the best surface for the potatoes to crisp up as a crust can form. Be sure to take a look at my step by step photos, you want the outside of the potatoes to have a bit of a mashed potato look to it.
Cooking in advance:
Stage 1After peeling and chopping- Simply place in a large bowl, cover and place in the fridge for 1-2 days.
Stage 2After par boiling - Drain, allow to cool completely and then place in a large bowl, cover and place in the fridge for 1-2 days. Then follow the cooking instructions as normal on the day.
Stage 3After roasting - Allow to cool, cover and place in the fridge for 1-2 days. Reheat by placing back in the oven for 20-30 minutes on the day.
If you want to prepare even further in advance you can freeze them after stage 2 or stage 3. Simply allow to defrost and either completely roast for 90 minutes if stage 2 or reheat by baking for 20-30 minutes if stage 3.Leftovers:IF you have any leftovers (never is in our house) then simply refrigerate for a few days and have with leftover roast, side dish to another dinner or add them to soup.Serving Suggestions: