Raw to cooked in 21 minutes. Who said fast food can't be good food. I had fun a few years ago with my friend's oven to see how fast I could make roast potatoes with the desiree potatoes dug up from the garden. After a few attempts I got it down to 21 minutes from raw potatoes to being crispy roast. You need a combi oven/ grill setting, but most new ovens have these.
Rosemary roast potatoes
Boil potatoes for 10 minutes. While these are boiling set your oven to combination oven and grill on the top setting. Place a baking tray under the grill to heat up. When the potatoes have been boiling for 9 minutes, pour vegetable oil on to the tray, or goose fat if you prefer this, and place this under the grill to heat. Drain the potatoes and let them sit back in the pan for 1 minute to steam (they need to be dry on the outside to go crispy). Then (a Delia trick) put the lid back on the pan and shake so they go fluffy on the outside.
Slide the potatoes on to the tray carefully as the hot fat splashes scar you for a few weeks - chefs wear long sleeved jackets for a reason, and this is the time when you roll the sleeves down. You could wear oven gloves or roll a tea towel around your wrists. Roll the potatoes in the hot oil/ fat using a palette knife, and leave lots of space between them, otherwise they steam rather than roast.
When they are almost finished roll in chopped rosemary and place back in oven for a minute so the rosemary sticks to the potatoes.
What if I don't have a combination oven/ grill?
If you don't have a combination oven - a normal oven is fine they just take longer.
Can I grill roast potatoes?
Yes - this works too. Instead of putting them in the oven once parboiled, dried (letting them steam for 10 mins) and rolling in [olive] oil, put them under the grill. You need to keep an eye on them though and keep turning them once they brown on each side.
Can I cook roast potatoes the day before?
Yes! This will make your Christmas cooking easy. Cook them completely as above. Let them cool and leave them in the fridge overnight. Then re-heat in the oven at 200 oC for around 15 - 20 minutes. See notes on dry heat below.
Can I freeze roast potatoes?
You can of course freeze these - and heat them in the oven for 25 - 30 minutes when you cook your Sunday roast.
How do I make roast potatoes go crispy?
DRY HEAT – Like yorkshire puddings, roast potatoes really like dry heat. When you open your oven door with the roast beef & roast vegetables cooking you’re likely to get a good head of steam escaping. If you try and put the potatoes in with the roast they always have trouble crisping up because there is too much moisture.
There are two solutions -
1 - Pre-cook the potatoes on the day or the day before and leave them chilled in the fridge, then re-heat them in the oven after the roast meat has come out to rest. Or you could freeze them (see above).
2 - Use a seperate oven - most cookers have two ovens.
HIGH HEAT - Roast potatoes like high heat to get them crispy, about 240 oC+. The high heat seems to work well - I cooked them at 240 oC the other day and they brown so well, as long as you remember to turn them.
FLOUR THE POTATOES - Another tip I picked up recently is to sprinkle a little flour over the par-boiled potatoes after being left to steam. Then toss them gently in the flour so it just coats the potatoes - you don't want a thick lump of flour - then add to the hot trays with hot oil, and roast as above.
What type of potato make the best roast potatoes?
Each type of potato has different properties - everyone says maris pipers, but I find these too floury. Personally in order of preference its:
ii King Edwards
Why don't my potatoes go crispy?
I read recently that if potatoes are kept too long the starch turns to sugar, so that obviously affects their browning/ staying together properties. I once ended up using some quite old estima potatoes from a veg shop and they fell apart before they even thought about browning - this is probably the reason. Supermarkets love to keep things as long as possble in warehouses, so again, if yours don't turn out so good this could be the reason.....
Also - see use of dry heat above, and remember it depends on what type of potato you use, again - see above. The cheapest bag of non-descript type of potato won't neccessarily give you the results you were after.
Also see high heat above - 240 oC for 20 - 30 minutes when there is nothing else in the oven making steam (e.g. your roast meat) gives you a crisp result, as long as you remember to turn them to avoid burning.