Jamie Oliver gets about a bit doesn't he? If he's not berating teenagers in the kitchen of his London restaurant-cum-community project, Fifteen, he's popping up in school canteens and government offices lecturing on the evils of turkey twizzlers. And now he's heading to Cornwall to lick a group of disadvantaged youngsters into shape in his latest venture, Fifteen Cornwall The restaurant opens on May 18 and will no doubt do for Newquay what seafood chef Rick Stein has done for Padstow (or "Padstein" to the locals).

But while these celebrity chefs reel in the visitors to the northern coastline of the county, what of Cornwall's southern side? Where do you go to sample something a bit more upmarket than a chunky Cornish pasty and a cream tea? It's a hard task, but I loosened my belt a couple of notches and set off to find out.

Truro
I wasn't expecting to experience the start of a weekend of culinary delights on a train. But breakfast on the comfortable sleeper from London to Penzance, served by a cheery attendant at some ungodly hour in the morning, consisted of a surprisingly buttery, flaky croissant and a decent cup of tea.

We jumped off the train in the cathedral city of Truro and made our first stop at local restaurant, Saffron. Tucked away down a back street, this centrally located restaurant - like many we were to visit in the coming days - sources all of its produce locally. It caters well for vegetarians (me) as well as carnivores (my travelling companion, Vicky).

The cauliflower, potato and cheese frittata and, I'm reliably informed, the warm cod salad with apple, beetroot and a poached egg were superb.

Saffron runs seasonal menus alongside its regular offerings, including a menu entirely based around asparagus from the end of April to mid-June and one designed around strawberries over the summer. The salad of strawberries, halloumi cheese and pine nuts with saffron toast washed down with a Fruli strawberry beer is enough to tempt me back for another visit.

St Ives
Our next stop was St Ives. For first-timers to Cornwall - such as ourselves, I'm embarrassed to confess - this beautiful town epitomises the county's picture-postcard image. Whitewashed fishermans' cottages line the maze of narrow windy streets, which take you up a hill flanked by a picturesque harbour and a long sandy beach - all overlooked by the somewhat disappointing Tate St Ives.

We were staying, and dining, at the Garrack hotel (perched on top of a hill, the hotel has breathtaking views over Porthmeor beach, where you can check out the surfers each morning as they try to catch the waves. The hotel was once a small gentlemen's residence but was bought by the Kilby family 40 years ago and converted into a hotel. Michael and Stephen Kilby, the sons of the original Kilby owner, have retained the feel of a cosy, rambling, old-fashioned family house. After a long day's coastal walk a big stuffed armchair in front of the log fire provides the perfect place to relax and read a book, or just listen to the ticking of the old grandfather clock in the hall outside.

Even if you're not staying at the Garrack, its restaurant is well worth the trek up the hill (don't bring your car - the wine list contains over eighty different labels from more than a dozen regions and then are the 19 different types of gin behind the bar ...)

Vegetarians are catered for but the restaurant's speciality is seafood, sourced locally from the port and market at Newlyn. Vicky made enthusiastic noises as she tucked into the steamed Cornish mussels with lemon grass, ginger and spring onions and there are fresh lobsters straight from the holding tank for those who like their crustaceans. Rooms are from £65pp on a bed and breakfast basis, and from £86pp including dinner. Their four-course daily set menu is £25.50 exluding drinks.

Mousehole
If you're heading off from St Ives for a day out in Penzance and the weather is good, take the 30 minute train ride along the coast (change at St Erth) for fantastic views. From Penzance, it's a short drive (or taxi ride) to the village of Mousehole, described by Dylan Thomas as "the most beautiful village in England".

We had the misfortune to arrive on a drizzly day but not so bad that we couldn't appreciate the panoramic views from the huge windows in the restaurant at the Old Coastguard Hotel. The restaurant looks out over sub-tropical gardens straight across the waters of Mount Bay and, on a good day, to the country's most southerly point, the Lizard.

Last year, The Observer Food magazine voted it one of the 100 best restaurants with a sea view in the country. The rooms in the hotel and the restaurant have a modern, white, clean and bright feel - not dissimilar to some of the upmarket beachfront restaurants you find in Sydney. The menus change daily and, again, the food is sourced locally with fish straight from the local fish market. The vegetarian option - which that day was grilled figs, goats' cheese and fine bean salad - was excellent, though Vicky said her baked herring salad was a little dry. Room rates start at £80 a night for a standard double in the low season to £160 for a premium plus double in the high season.

The Lizard
Next stop is The Lizard and the Landewednack, which bills itself as an upmarket bed and breakfast.

Owners Erik and Sue Thorbek and their private chef, Antony Taylor, live in one section of the restored 17th century house along with half a dozen pugs and two enormous Persian cats. Jam-packed with trinkets, china figurines and paintings, the house stands in front of almost two acres of gardens which lead down past vegetable patches and on to a secluded heated swimming pool and jacuzzi.

Over the hedge at the end of the garden is a tiny, 1,000-year-old church, whose bells still peal before a Sunday service. Walk further down the lane behind Landewednack, past the thatched cottages and you come to Church Cove, just east of the Lizard.

The emphasis at Landewednack is on getting to know your fellow guests (although large parties can hire the whole place to themselves). Visitors are encouraged to eat together, swap stories in front of the blazing log fire and, in the summer, play croquet or boules on the lawn. The evening we dined there - mahogany table, candlesticks, crystal wine glasses - Antony served a spinach salad with parmesan and bacon followed by cod, potatoes and vegetables. I ate a delicious Roquefort, leek and mushroom tart - and got to take the remainder home with me the next day.

Up to 15 guests can stay in the property (including in the adjoining coach house) and room rates start at £120 a night.

The Helford River
The final stop - and for me the highlight of the weekend - was at Trelowarren. It's a rugged, hidden away, historic 1,000-acre estate on the Lizard peninsula. In her book Frenchman's Creek , Daphne du Maurier described it as "the most beautiful place imaginable ... shock, surprise and delight, lying like a jewel in the hollow of a hand".

It's current owner, Sir Ferrers Vyvyan, has set about converting some of the estate's old buildings into liveable properties as well as building new eco-friendly cottages. These are all being sold on a timeshare basis but can be used as self-catering holiday homes at other times (see this article for more information). The estate is also home to the award-winning New Yard restaurant, which is housed in a converted carriage house, standing in the 18th century stable yard.

Chef Greg Laskey uses local produce wherever possible and changes the menu with the seasons. Sample dishes include roasted monkfish served with sweet butter cabbage and finished with creamed parsley and fois gras sauce. An example of dessert is hot chocolate fondant with whisky ice-cream.

You can visit Trelowarren just for the food - but once you have a look at the surroundings and the accommodation you probably won't want to leave.

Way to go

· Lisa Bachelor travelled to Cornwall courtesy of First Great Western trains. Jamie Oliver opens his latest Fifteen restaurant in Watergate Bay on May 18

For more information see www.visitcornwall.co.uk