I was in a restaurant last week when the waiter appeared, poured half a glass of wine, and lingered at my elbow. I tried to resume my conversation, but his presence gnawed at my concentration, and after a few seconds I'd had enough. "What is it?" I snapped, voice unexpectedly high. "You're not a hotel porter, you know. If I decide to give you a tip, it'll be at the end of the meal and not before, you scrounger!"

"Would you like to try the wine, sir?" asked the waiter, moments before I would have said any of the above, had I thought of it. I sipped my drink. Ah yes. A bitter, vinegary taste, infinitessimally fruity. A certain wine- like quality. Yes ... I'm almost certain it's wine. And judging from the colour and the temperature, it's white wine, and you haven't brought me a bottle of lighter fluid by mistake. Which is exactly what Jancis Robinson means when she goes on about a mischievous hint of wood shavings and khaki enamel paint.

"Delicious," I told the waiter, and he seemed satisfied. If the exchange had had any point other than the observance of obscure tradition, then it had escaped me. Wine, after all, is not a particularly erratic product. It's bottled and delivered in bulk. Why not give me the option of returning the ketchup, too?

Food is a different matter. I've never seen anyone reject a bottle of wine, but almost every time I've eaten out I've yearned to swap my pathetic hunk of sponge for the chocolate ice cream sculpture that they're eating at the next table.

But, no, order a meal and you're stuck with it. I was once near Loch Ness, and stopped at an inn with my friends, Bert and Trevor. Those aren't their real names, but one of them figured prominently in last week's column, and I want to give the impression that I have tons of mates. Outside the inn there were half a dozen options on a blackboard, written to make each dish seem three times as substantial by listing the ingredients as if they were bonus extras. "Lasagne," it promised, "with minced Ayrshire beef, onion, garlic, tomatoes (chopped and pureed), slices of fresh Italian pasta, plus both mozzarella and parmesan cheeses," it said. "Sea salt and black pepper optional." That was before it got started on the salad. I wasn't sure that I'd have room.

Trevor asked the Australian waiter if the lasagne came in a big portion. "We've been walking all day," he explained, in a tone that hinted at mountains and crampons, and not dawdling along the road, pretending to see the Monster. The waiter assured us that the portion was gigantic, although I don't suppose he would have told us that, actually, the inn was famous from Inverness to Fort William for its measly servings. He should have done, though. The lasagne hid in a bowl the size of a coffee mug, alongside one slice of tomato, a piece of lettuce and an onion ring. If this was a big portion, then my cod was the Monster we'd pretended to see.

Nevertheless, we tucked in, and when we'd finished, three minutes later, we were preparing to settle the bill when the waitress began to chat. Once we'd become pals, she asked if the meal had been all right. Actually, remarked Trevor, the serving was quite small. She laughed at this good- natured teasing. No, really, he repeated, it was quite small. The smile crumbled from her face. Obviously, the only sane reply to "Was your meal all right?" was in the affirmative. "No one's complained before," she stammered, traumatised, and called over her Australian colleague. He opted for a more brazen approach. "Whatsamatter?" he demanded. "You got worms or something?"

Horribly soon, a suspicious gang of staff had emerged from the kitchen, looking as mean as they could in white aprons (which was pretty mean), and quite probably bearing concealed meat tenderisers. The manager marched to the front of their ranks. "Is there a problem with paying the bill?" he demanded. The idea of not paying hadn't crossed our minds. We had materialised in a "how did this happen?" situation. Our actions had seemed to make sense, but at some unknown point we had made a critical error and slipped into the twilight zone. You ask a waitress's question honestly and politely, and you end up being lynched for attempting to defraud the owner out of a scoop of pasta.

His respectable establishment, he said, could do without a bunch of hawking, troublestarting students insulting his chef and "barking" at his waitress. I shan't mention the name of the inn in question, but I do know it, and unless I receive a lasagne in the post by Tuesday, the readers of this newspaper are going to know it, too.

Suzi Feay is away