The long, thin restaurant is a couple of doors down from The Avenue (flavour of the month when it opened in December) and next door to one of the country's most venerable wine merchants, Berry Bros & Rudd, which has been at No 3 for two hundred years. The passage between these two is reckoned to contain timbers from the original farmhouse (yes, farmhouse) that occupied the site before that, and which supplied food to the hospital (founded in 1100) for "leprous maidens" across the road that eventually became St James's Palace.
At the front is a narrow bar, empty as we passed through for lunch, though it looked as if it could support a few champagne guzzlers and oyster swallowers if the management put its mind to it. (And until a few weeks ago, when it was Overton's fish restaurant, it used to.) Next comes the pinched waist of the room with banquette seating where we sat and honed our passive smoking skills. Then comes the dining room proper, carpeted, generously spaced, absorbing daylight through the glass roof and looking on to Pickering Place, a quiet, hidden, flagged courtyard that positively aches to be filled with tables in fine weather.
"Why is it called L'Oranger?" we asked. The maitre d' didn't know, except that it was meant to conjure up a Mediterranean feel. So might "Bouillabaisse". Nor does the menu help, since it is not particularly Mediterranean in outlook. Rabbit leg confit, saddle of lamb with a rosemary jus, and braised ox cheek indicate a timeless Anglo-French perspective.
Cream of celeriac soup was exceptionally good. It came looking frothy, as if somebody had blown bubbles through it with a straw (though I'm sure they hadn't) and tasting strong and delightful. Guinea fowl (breast and leg) also came with a little cream in the tarragon sauce, though it wasn't too rich. This was accurately timed cooking, with relatively plain accompaniments of braised lettuce and spinach, impressive for not being too fussy.
We had asked about vegetarian dishes twice (once when booking, again when confirming) and were assured there would be something available. This came as a complete surprise to the maitre d' - whom I shall call Dominique, since that is his name - but he popped into the kitchen (you can just see it through frosted glass at the far end) and a first course pasta dish was quickly adapted into a very successful main course: a single, thin raviolo enclosing a mix of mushrooms, set in a lightly creamy sauce strewn with chopped vegetables and aromatised with truffle oil. Drops of truffle oil had also been drizzled over a first course of roasted scallops to good effect. This is a quick and easy (and relatively inexpensive) way to add an exotic note to a dish, though it only works if used sparingly. Two in one meal is perhaps one too many.
The scallop dish brought to light another of Marcus Wareing's hobbies. He chops things up - vegetables and fruit particularly - into very tiny dice. Although this can make a red pepper or a peach go an awfully long way, and looks as though you care enormously, the material loses something of its textural appeal, and (because there is so little) forfeits something of its taste. The "ratatouille" (another good name for a Mediterranean restaurant) underneath the scallops was made up of these tiny bits, as was the "fruit salad" arranged in a fairy ring round an exceptionally good banana parfait, whose success was partly due to the embedding of fine layers of crispy chocolate.
By this time we had spectacularly failed passive smoking and Dominique had kindly moved us (us, mind, not the smokers) to a table where we could now see the Toulouse Lautrec prints. Surely they can do better than this in St James's? It is to be hoped that some penniless artist will drop by for dinner and pay for it with a canvas. The good news was, we could now taste the food properly. The "fine plum tart" was made to order, with slightly flaky pastry, but the plum was sliced as thin as a sheet of filo. What I really wanted from it was something juicier, more heartily plum-like. The dainty visual expressions that Marcus Wareing goes in for seemed to be in danger of getting the upper hand.
We drank a bottle of Cape Mentelle Chardonnay (pounds 22) from a list that included decent Chilean and Californian bottles to balance the upmarket French one, but mark-ups are on the high side. We paid pounds 19.50 for a three-course lunch (dinner is pounds 22, same style, a couple more dishes), and reckoned it was good value, though why there should be a supplement of pounds 2 for scallops is even more of a mystery than the restaurant's name.
I have left until the end (for those who don't already know) the reason why L'Oranger is expected to make a big splash. Marcus Wareing is a protege of Gordon Ramsay at the Aubergine in west London (Dominique came from there too), though it doesn't do to think of this as Aubergine Two, since it would suffer by comparison. Best to pick a fine day, book a table outside (dinner only, May to September) and enjoy it for its own sake.
Jim Ainsworth is editor of 'The Good Food Guide 1996'Reuse content