Tip the potatoes into a large tray in one layer, and add the fat – olive oil, butter or goose fat – then season really well with sea salt and black pepper.
Wash your potatoes and parboil until almost tender, then drain. Pick and bash the rosemary leaves. Drizzle with just a little touch of oil and roll in a teaspoon of sea salt, a little freshly ground black pepper and the rosemary. Put the potatoes in a roasting tray and cook in the oven for 25 minutes until golden.
Roasted potatoes can become soggy if the water content in the potato isn't fully cooked. Different potatoes have different water content percentages. Also, be mindful of the oil. Potatoes can react like sponges; too much oil can make your potatoes appear to be soggy.
Boiling your potatoes for a little bit before roasting helps make sure that you get that beautiful crisp crust on the outside. If you don't parboil your spuds, the outside skin will remain quite tough, meaning that whatever fat you use will not be able to get inside the cracks.
Peel the potatoes, keeping them whole, and ideally all about the same size (8cm). Parboil them in a pan of boiling salted water for 15 minutes – this will ensure that the insides become really fluffy.
Best cooking oil for roasting
Extra virgin olive oil and coconut are both good for slow roasts due to their low smoke point and added flavour, whilst vegetable oil and rapeseed oil are neutral, medium smoke point oils that are versatile and can be used in most roasts.
Oils with a mild flavor and a higher smoke point are best for roasting potatoes as they can be heated to the higher temperatures used in roasting. These oils include light olive oil, canola, and grapeseed oil.
Vegetable oil is the ideal choice for those who like a subtle, or blander flavour from their roast potatoes, because it cooks best at a medium heat and so the potatoes won't take on too much flavour from the oil. This also means the potatoes won't overpower other dishes.
To make crispy roast potatoes, the temperature of the oven needs to be hot. If the oven is too hot the potatoes will burn before they crisp up. If the oven temperature is too cold your potatoes will not be crispy.
“Loads of olive oil, garlic purée, salt and brown sugar, and toss your potatoes,” she advises. “Toss them, then roast them and you are instantly getting all of that flavour in the salt, the sweet and the garlic – all of that massive flavour onto these potatoes. It's my favourite thing ever.”
BOIL THEM BEFORE ROASTING
You want enough salt that you can really taste it in the water. Bring slowly to the boil then, once the potatoes are at a proper rolling boil, reduce the heat so they simmer at a steady pace. Now start the timing: 2 minutes is the minimum; 10-15 should be right for large potato pieces.
Soaking potatoes in water helps remove excess starch. Excess starch can inhibit the potatoes from cooking evenly as well as creating a gummy or sticky texture on the outside of your potatoes. Cold water is used because hot water would react with the starch activating it, making it harder to separate from the potatoes.
Preheat the fat. While the potatoes parboil, add the oil or butter to the roasting pan, transfer it to the warm oven, and heat it for about 5 minutes before adding the potatoes. This allows the outside of the potatoes to crisp up nicely and not just absorb the cold fat when you put them in the oven.
The salt traps the moisture that escapes the potatoes while cooking, allowing it to be reabsorbed by the potatoes, and produce awesome results. And if you uncover the potatoes from the salt for the latter part of the baking process, you get crispy potato skin too.
For vegetables, chicken, and just about everything else, olive oil and ghee are our first choices for roasting at temperatures over 400°F. Not only do they help food cook up with the crispiness you crave, but each one also imparts its own unique flavor that you just don't get from neutral oils like grapeseed or canola.
But one oil stands out for its superior ability to add extra crunch to those roasted spuds. Traditionally, vegetable oil, grapeseed oil, and canola oil are used for roasting potatoes. But while not as commonly used, sunflower oil is an even better option for the roasted potatoes of your dreams.
While olive oil does taste great with potatoes, it also has a lower smoking point. The solution: mixing EVOO with vegetable oil (or another neutral oil with a high smoking point). The best kind of potatoes. Use baby Yukon gold if you can!
Canola has a neutral flavor and a high smoke point, so it's handy for stir frying, roasting, grilling and pan-frying. It's a good substitute for vegetable oil when baking – just swap out equal parts.
For example, the point of searing is to get color and caramelization on the outside of a food, which can only be done over high heat. If you try to sear with olive oil, the oil will smoke before it gets hot enough to sear the food. Or, if you roast olive oil-coated vegetables at 425°F, the oil will burn in the oven.
While it's true that olive oil has a lower smoke point than the likes of sunflower, vegetable and rapeseed oil, it's still high enough to roast and sauté with.
Parboiling is different from blanching in that after parboiling, you rinse the food under cold water, to stop it from cooking, then cook it further when other ingredients are ready, or you store it for later use. By contrast, blanching does not require a cold rinse or bath.
For most potato dishes it's important to add the potatoes to cold water and allow the water to come to a boil with the potatoes in the water. The potato starch can react as soon as it comes in contact with hot water, which will promote uneven cooking and mealy potatoes.