‘In or out?” The question that the pourer of the Angostura bitters used to ask in the days when we drank pink gin applies in more recent times to the matter of where we eat during the supper interval on a visit to a country house opera. Will it be an expertly prepared meal in the venue’s official restaurant, or a picnic out in the sunshine (oh yeah?) or in one of the little tents usually available for hire?

On the idyllic Wormsley estate, the new home in the Chilterns to Garsington Opera, the restaurant is in the capable hands of Bicester-based Jamie Oliver’s Fabulous Feasts. The company can take much of the pain out of picnicking, too, by offering food ready to go. You can have, for £39.95 a head, a lavish meal of cured salmon, quiche lorraine, strawberries and raspberries, passion fruit and lemon posset, and more, laid out on a table overlooking Mark Getty’s famous cricket pitch. Sixty pounds buys two people a hamper containing (yum, yum) rare roast beef, Scotch egg, smoked salmon, that quiche again and salads, plus summer fruits and lemon drizzle cake. Eat it where you like.

On two visits to Wormsley last week we were both in and out — happily in the right order. On Monday, we had a picnic beside the lake of our own devising: prawns, asparagus, Aldi four-bird roast, strawberries, cheeses, and — in honour of Her Majesty — Jubilee teacakes, shortbread and the like. It was mightily cold but at least it didn’t rain. On Tuesday, it was still bitter for June and hideously wet as well. Overcoats, umbrellas and blankets were de rigueur. Two people who followed us into the restaurant marquee were so buried in protective clothing that they reminded me of people you used to see handling radioactive isotopes in sci-fi films.

Unheated though it was, the marquee proved,what with all the bodies and the arrival of hot dishes, an oasis of warmth from the arctic conditions beyond the zipped plastic door panel. But, alas, people did need to come and go through it . . .

Flowers, candles, gleaming glasses and brilliant white tablecloths supply the up-market feel you would expect at a meal priced at £55 a head, with some supplements. In the circumstances — where it was being served, the charm of the well-drilled staff serving it (only white shirts — brrr! — with braces for them) and the quality and imagination evident in the dishes themselves, this did not seem exorbitant.

Readers of the print version of this article can see all that was offered to us over on the right, captured by Rosemarie’s camera. Website readers will see some of it. Visual appeal is therefore clear. As for taste, I would say that the products of Dan Mann’s mobile kitchen have the up-front flavours for which Jamie Oliver is noted and which are certainly evident at his Jamie’s Italian restaurants, of which the Oxford branch was the pioneer.

In a recent interview with Helen Peacocke, Dan spoke of the vital importance — obvious really — of getting so much food out to so many people hot and fast. This was no problem where our starters were concerned, both of which were cold anyway. I was impressed with my ‘grilled and chilled’ asparagus, served with shavings of Lancashire cheese, honeyed walnuts and rapeside oil, and Rosemarie’s hot-smoked salmon and hand-picked crab with avocado, tomato and parsley (£4 supplement) was admirable, too.

But when it came to the main courses Dan’s team really showed its mettle. My “fruits of the British seaside” (no camp jokes please) arrived steaming at the table. There was a scallop with pea purée, mashed potato-topped fish pie, and a Venetian-style fish stew with tomatoes and tiny pasta balls. The only ‘fish’ present in the last were mussels, not of course fish at all. This did not bother me, but could bother others, some of whom might be allergic to shellfish. The whole dish (supplement £7.50) was too substantial for some people’s taste (even mine).

Rosemarie’s ‘pulled’ (what that?) slow-cooked Oxfordshire lamb may have puzzled with its name but certainly hit the spot taste- wise, with its vegetable broth and watercress and tarragon pesto. But (mystery No. 2) what was that vegetable that looked like an onion but tasted of nothing?

My English cheeses (Oxford blue, red Leicester and brie, £3 supplement) came with sensational seeded crackers (caraway and sesame) that I could have eaten all night — Vivaldi’s L’Olimpiade notwithstanding — and super fig jelly. Rosemarie loved her bitter chocolate tart with raspberries and honeycomb. After the chilly delight of Gavi di Gavi Cru Maddalena (£26.25), the coffee supplied welcoming warmth and was — as might confidently have been expected — excellent.