This week I have taken some everyday ingredients and given them a new twist with a drizzling of brilliant green parsley oil, which the Spanish love to dress so much of their food. I can understand its popularity; not only does the oil take only five minutes to make with a pestle and mortar, or blender, but it is also an easy way to add colour and vitamins to a dish.

Last week I had some friends coming for supper. I knew that I'd little time left to do the shopping and cooking but, as always, I felt some pressure to rustle up something delicious. Last-minute cooking can be fun. It forces you to think on your feet and come up with simple solutions that you can cook in the limited time you have and with limited ingredients.

I was a bit stuck initially and then I had a brilliant idea: parsley oil. I grabbed several enormous bunches of flat-leaf from a greengrocer on the way home. With only an hour to cook everything from scratch, tidy the house and lay the table, the oil was quickly rustled up in the pestle and mortar with a combination of chopped parsley, anchovies, garlic, olive oil and vinegar.

The oil, which should be dense with the chopped, green herb, keeps well in the fridge for a couple of weeks, although I can never hang on to mine for more than a few days.

You can mix it with virtually anything to create scrummy supper dishes. These three recipes show how it can transform grilled vegetables, add colour and depth of flavour to a simple dish of mushrooms and ham, or add a note of sweetness to spicy grilled chicken.

Any leftover oil can be used to transform parsnip and potato mash into a herby, nutty ambrosia or a simple plate of chicory leaves and apple into an elegant, emerald-flecked salad; good enough to be served in a smart restaurant. Even a toasted sandwich comes alive with a teaspoon thrown in.

Shopping List

3 or 4 bulbs of fennel

4 or 5 heads of chicory

4 or 5 parsnips

600g mixed mushrooms

1 chicken or 8 chicken thighs (free-range)

Serrano, Iberico or Parma ham

Star buy

3 large bunches of flat-leaf parsley

Store cupboard buy

Bottle of good sherry vinegar

If you don't have them already

Olive oil

A tin or jar of anchovy fillets

A head of garlic

Cayenne pepper

Potatoes

Peppercorns

Lemons

Recipe 1: Grilled vegetables with parsley oil

Preparation time: 15 minutes; cooking time: 20 minutes

To make the parsley oil, roughly chop a large bunch of parsley (about 100g) with 8 anchovy fillets and two fat cloves of garlic. Transfer the lot to a pestle and mortar

and bash together with some peppercorns and a teaspoon of sherry vinegar. Mix in 200ml of the best extra virgin olive oil you can afford and taste to check for seasoning; you may need to add salt or a little more vinegar to sharpen it up. You can also make the sauce by whizzing all the ingredients in a food processor. I always make as much as possible so I can store it in the fridge.

Put 4 or 5 parsnips in a pan of salted water and parboil until the parsnips are al dente, about 10-15 mins. Slice them in half and then slice the fat top ends lengthways into 1cm batons. The skinny tails can be left as they are or sliced in half along the length. Peel off the tough, outer skin from 3 bulbs of fennel and slice vertically into 1cm pieces. Cut the hard stem from 4 or 5 heads of chicory and slice lengthways into quarters. Toss all the vegetables, which should all be in generous, similar-sized chunks, in a few tablespoons of olive oil and season well with Maldon sea salt and pepper (remembering that they will also be dressed with the parsley oil at the end).

Heat up a heavy-ridged pan or char-grill until smoking hot and add the vegetables. Cook them 3 or 4 minutes a side until they are cooked through and decorated with smoky black lines. Toss the vegetables in enough parsley oil to coat generously and serve them in a large plate at the table. They are delicious with roast pork, lamb chops, or simply on their own with a plate of white beans, or chunks of good bread.

Recipe 2: mushrooms and ham with parsley oil

Slice 600g of mixed mushrooms (chestnut, flat-cap, button, oyster, or any mix will do, morels would be wonderful if you can track some down, they are just coming into season). This is a very therapeutic job so settle yourself in a corner and slice away, finding your rhythm. Heat a fat knob of butter and a tablespoon of olive oil in a large frying-pan and fry half the mushrooms - it's better to do this in two batches - and a clove of chopped garlic for 5 minutes, seasoning well with plenty of salt and pepper. Repeat with the rest of the mushrooms. Serve as a starter or a light lunch with strips of Serrano, Iberico or Parma ham tossed in and drizzled with parsley oil.

Recipe 3: Spicy grilled chicken with parsley oil

Segment a whole chicken or buy 8 chicken thighs. Season them with salt, cayenne pepper, the juice of half a lemon and enough olive oil to coat them. Marinate for half an hour and then grill until charred and delicious. Serve drizzled with parsley oil and a bowl of mashed potatoes.

Explore Food & Drink

• Gordon Ramsay

• Heston Blumenthal

• Recipes

• Wine

• Real Food

• Anjum Anand

• Eating Out

• Video Recipes

Times Recommends

• How to season a wok
• Chicago Rib Shack hits back at its critics
• Gordon Ramsay: Indian barbecue