I like the décor cared-for but not stuffy. The food must be fresh, local and seasonal, a good chef at the stove and with friendly service. And, finally, they will have a good choice of beers, guest ales and many wines by the glass. With all of that in place, I can be forgiving of any other misdemeanours.

I thought I had found perfection in the Crown at Roecliffe, a 16th-century coaching inn just outside Boroughbridge.

The village is picture-perfect and even from the outside the inn looks inviting, all spick and span, and it gets better on the inside. There are three distinctly different rooms to choose from. There's a cosy bar with dark wood tables, terracotta coloured walls and a flagged floor; a posh-looking restaurant smartly dressed in white cloths, sparkling glasses and silverware; and there's the Green Room, somewhere between the two.

Sprinkled throughout are homespun touches of country furniture and magazines, even a cat curled up by the fire – which, on closer inspection, I discovered was stuffed.

The menu tickles the taste buds in all the right places, merrily galloping through meats and fish, a nod at vegetarian and a daily specials board, even the prices were reasonable. It's one of those menus to consider slowly and carefully over a glass of wine – and there were plenty to choose from. I had that delicious feeling of having uncovered a gem of a place.

More-ish breads, as warm as the waitress's smile serving them, was a good start. A high mound of crisp, golden, tempura prawns raised the bar another notch and the (I quote) "Now nearly famous Whitby crab soup" had the bar soaring. It deserved the proclaimed status with a rich, deep flavour and a generous body of white and dark crab meat. The glass of French Viognier slipped down easily alongside, demanding a rapid top-up in preparation for the next course.

Rare breed minced beef and beer pie with a herb suet crust seemed intriguing. What have they done to mince to raise it alongside the other offering of rib-eyes, sirloins and beef daube on the menu?

As it turned out, not much. It was quite simply mince. No beer flavour came through in the otherwise rich sauce and the promised root vegetables had changed personality to roasted Mediterranean vegetables – not great partners for a suet crust.

As a mince pie it was satisfactory, there was plenty of it, but a crack had appeared in the image of the perfect pub.

Maybe the daily fish special would plaster over it. Carrying on the local theme was a piece of Whitby halibut, which, in their words, was baked to flaking atop a mussel sauce and a Parma ham crisp.

From the moment the dish wafted on to the table, there was a sense of something not quite right. Rather than sitting "atop" the mussels, it balanced precariously at the side of the plate. The halibut may at some point in its short life been flaking, but this one had become solid. What's more, there was no Parma ham crisp.

An odour drifting up from the plate made me nervous. I must have looked like Samantha of Bewitched fame with my nose twitching trying to detect the source of the smell. It was the mussels. True, it may have been just one, but it only takes one to bring on serious upset. A discreet word with the waiter and they disappeared accompanied by profuse apologies. Well, it can happen to anyone. What should not happen, however, was the response. "Chef says there's nothing wrong with the mussels, so he's making you some more," I was told. "Tell him not to bother," was my reply.

The halibut reappeared, this time fresh and flaking. It was "atop" a creamy sauce and a couple of fresh asparagus spears. Simple, perfect and delicious. But still no Parma ham crisp, I hadn't the heart to ask for it.

The puddings here have an equally tempting appeal as the rest of the menu, with Fruit Cobbles, Trios of this and that, Lemon Tart and our choice, a melting chocolate pudding and custard.

The pudding was more than acceptable, it melted fittingly, oozing into thick custard, so no complaints there.

Had all the food lived up to its early promises, I would have felt the £67 bill for two including wine reasonable.

So many boxes had been ticked in my list of a perfect pub, they were so close to hitting the jackpot.

The Crown is clearly a professionally-run operation and has all the makings of being one of the county's greats.

Could someone, however, please tell the chef that it's a good idea to serve what it says on the menu? And remind the kitchen that the old adage – the customer is always right – is correct, especially when it comes to mussels.

The Crown Inn, Roecliffe, Boroughbridge, North Yorkshire YO51 9LY. 01423 322300. Open daily, lunch noon-2.15 pm, dinner 6pm-9.30pm, Sunday noon-7pm.