Mary Berry's recipe notes state that a roast potato should be ultra crispy on the outside with a fluffy light middle. The chef's method involves par-boiling and roughing up the potatoes before roasting, with semolina adding an extra crunchy coating.
The semolina technique
Semolina is the secret to achieving exceptionally crispy, crunchy roast potatoes. When the potatoes are tossed in semolina before roasting, it roughens their surface, creating numerous small edges that crisp up beautifully during cooking.
It also helps absorb excess moisture, allowing the exterior to dry out and achieve a delightfully crispy texture. Fine or medium semolina is ideal, though it should be used sparingly, as too much can cause the potatoes to burn and develop a slightly grainy texture.
Ingredients and preparation
The recipe serves six people and can be prepared up to 12 hours in advance. The potatoes can be partially roasted for 35 minutes until golden, then finished in a hot oven for approximately 20 minutes just before serving.
Ingredients include 1.5kg old potatoes, peeled and cut into medium-sized cubes, 40g semolina, four tablespoons of goose fat or vegetable oil, three thyme sprigs, and salt.
Method
Preheat the oven to 220°C/200°C Fan, then place the potatoes in a saucepan of cold salted water. Bring to the boil and cook for around five minutes, until the edges begin to soften.
Drain in a colander until thoroughly dry, return to the saucepan and shake vigorously to roughen the edges. Sprinkle over the semolina and shake once more until evenly coated.
Preheat a large, shallow roasting tin in the oven until hot. Add the fat to the tin and heat for five minutes until smoking. Carefully add the potatoes, turn in the fat until coated and scatter over the thyme sprigs.
Return to the oven and roast for about 45 to 55 minutes until golden brown and crisp. Be sure to turn the potatoes halfway through the cooking time. Serve piping hot with your roast dinner.
Semolina also works brilliantly for making pudding and porridge, and for coating dishes, chicken, or vegetables to add a satisfying crunch.
