Why Olive Oil Earns Its Place on the Hob

British cooking has always been generous with fat — butter for toast, lard for pastry, a glug of sunflower oil in the chip pan. Olive oil is not here to replace any of that. It simply slots in more comfortably than most home cooks expect, especially a straightforward, fruity extra virgin that adds warmth and a faint peppery edge without shouting over the flavours you already know.

You are not suddenly cooking Provençal food. You are cooking a Sunday roast, a fish pie, a bowl of new potatoes — and choosing a different fat to do it with. A useful rule of thumb: keep a mid-range bottle for the pan and save the delicate, expensive stuff for finishing. Everyday extra virgin olive oil is perfectly happy roasting at 200°C, so there is no need to buy a refined "light" oil unless you are deep-frying at chip-shop temperatures.

Roast Potatoes, Done Slightly Differently

This is the easiest swap to get right. Peel and cut your potatoes into thirds, parboil them for eight minutes in well-salted water, then drain and leave them in the colander for a minute to steam dry. Shake them about until the edges fur up, then dust with a tablespoon of semolina or plain flour.

Meanwhile, put four tablespoons of olive oil into a roasting tin and heat it in the oven at 200°C fan (220°C conventional) for five minutes until it shimmers. Tip the potatoes in carefully, turn them to coat, and roast for 45 to 50 minutes, turning twice. The result is a shell that is crisp and slightly nutty, with a soft, floury middle. It is not the same as goose fat, but it is very good — and it means vegetarians at the table can eat the same potatoes as everyone else.

The same approach works for Yorkshire puddings: a teaspoon of oil in each hole of the tin, heated until it is almost smoking, then batter straight in and 20 minutes at 220°C. The edges come out shatteringly crisp.

Fish Pie, Shepherd's Pie and Other Comforts

White sauce is where olive oil proves itself quietly. Make a roux with 50ml of olive oil and 50g of plain flour, cook it out for a minute or two, then whisk in warm milk a splash at a time. You lose the dairy richness of butter but gain a savoury depth that suits fish beautifully, particularly with a grating of lemon zest and a spoonful of mustard stirred through.

For the mash on top, warm two tablespoons of olive oil with the same quantity of milk and beat it through the potatoes instead of butter. It gives a looser, glossier mash that grills well.

• Traybakes: drizzle two tablespoons over sausages, chicken thighs and root vegetables before roasting at 200°C.
• Roast chicken: rub the bird with oil, lemon and salt rather than butter — the skin crisps more reliably.
• Fried eggs and garlic: a modest pool of oil in a cold pan, brought up gently, gives softer results than a screaming hot frying pan.
• Fish: rub fillets with oil, salt and paprika and roast for 12 minutes at 200°C.

Dressings, Salads and Cold Uses

Cold is where olive oil tastes most like itself, so this is the place for the good bottle. A classic vinaigrette is three parts oil to one part vinegar or lemon juice, with a teaspoon of mustard, a pinch of salt and a good grind of pepper. Shake it in a jam jar and it will keep in the fridge for a week; bring it back to room temperature before using, because cold oil tastes dull.

New potatoes, boiled and still warm, take two tablespoons of oil, a squeeze of lemon and a handful of chopped mint. Tomatoes benefit from oil, salt and a few minutes of sitting. Even a plain green salad improves with a lighter hand than most of us use — a tablespoon is usually plenty for four people.

A Note on Baking and Everyday Frying

Olive oil cakes are having a moment, and rightly so: they stay moist for days and suit orange, rosemary and dark chocolate. As a rough guide, replace 100g of butter with 75ml of oil and reduce any other liquid in the recipe by a tablespoon or two. Be cautious with very delicate sponges, where a robust, peppery oil can taste oddly savoury — use a mild, buttery oil for those.

For hard frying, olive oil will smoke before sunflower or rapeseed does. Keep it for shallow frying, roasting and sautéing, and use a high-smoke-point oil for anything above about 210°C.

Buying and Keeping It Fresh

Olive oil is a fruit juice, and it declines. Look for a harvest date rather than a best-before date, and buy something bottled within the last 18 months. Dark glass or a tin protects it from light; a cool, dark cupboard protects it from heat. Do not store it beside the hob, however convenient that feels.

Two bottles serve most kitchens well: a workhorse for roasting and a better one for the table. Buy smaller quantities more often, and use it — an oil that sits untouched for a year is a wasted one.