BAUGHURST, England — On a raw day when most of England is blanketed in a fog so thick you can almost feel its weight, a hearty lunch of cottage pie topped with cheesy mashed potatoes is the perfect antidote to the chill. The cozy dining room of The Wellington Arms, a pub and inn on a beautiful country road about an hour west of London, is just the setting in which to enjoy it.

Built in 1780, the building that houses this upscale pub sits at the edge of the Duke of Wellington’s former estate. According to co-owner Simon Page, who bought the property with his partner, Jason King, 10 years ago, it was said to have been used as a hunting lodge. Operated as a pub before the couple bought it, the building sat empty for three years. “It was a dump,’’ says King. “It had no garden at all. The trees had grown into the car park.’’

Meticulously restored and expanded over the last decade, with original wood beams, antique tables polished to a high gleam, and a welcoming fireplace, the dining rooms exude classic English country charm. As if to underscore the property’s provenance, an original painting of the duke’s coat of arms, unearthed during the renovation, holds pride of place on one wall.

Page and King also turned the roughly three acres on the property into lush, productive gardens and pasture. With their staff, they grow pumpkins, zucchini, eggplant, fennel, peppers, herbs, plums, rhubarb, and more, raise Jacob sheep and Tamworth pigs for meat, bees for honey, and keep rare breed and rescue chickens for eggs.

Those chicken come from the British Hen Welfare Trust, which finds homes for commercial hens that would otherwise be slaughtered. Here, the birds are free to roam the grounds from early morning until dark. A hoop house behind the kitchen provides a spot to grow salad greens year-round. Almost everything the staff doesn’t grow is locally produced, most of it organic. There are three guest rooms, one above the dining room and two in a restored barn. Page notes that Americans, in particular, are frequent guests, drawn in part by the inn’s proximity to Highclere Castle — also known as Downton Abbey — about 20 minutes away.

A chef born in Melbourne, King, 43, grew up cooking and began his career at 19 in his hometown. He went on to work in Paris, London, and Hong Kong, where he met Page, 45, a classical musician and educator. He cites Australian chef, restaurateur, and food writer Stephanie Alexander and renowned British chef Hugh Fearnley-Whittingstall, known for his commitment to seasonal, ethically produced food, as inspirations to grow and raise his own ingredients.

King oversees a part-time staff of about 45 in a relatively small kitchen that produces three meals a day for a 30-seat dining room (the kitchen can fit nine cooks at a time). Most are in their late teens to early 20s, all from the area, and all “absolutely obsessed about food,’’ he says. “Kids who come here to cook for me can’t peel a potato,’’ he notes. But under his guidance, “They learn things, they’re invigorated. I’m strict. I’m like their dad.’’

Menus at The Wellington Arms change almost daily. “It’s very ad hoc,’’ says the chef. But every day there is a soup, at least one vegetarian entree, a terrine, a souffle, and pot pie or stew, depending on the time of year. King has been gearing up for the holiday season since early November — prepping pheasants, peeling apples for jellies, and starting Christmas puddings using his grandmother’s recipes.

On this chilly day, lunch begins with a salad of greens with smoked chicken, sliced avocado, and paper-thin slivers of radish tossed with a bright vinaigrette that hits all the right notes. Cottage pie is fragrant with fennel, allspice, chile, and mace. Veering from tradition, King roasts the meat, then cuts it into tiny dice, rather than using ground beef, and he adds pork to deepen the flavor. The “cheesy mash,’’ rich, buttery potatoes laced with cheddar, goes on top and is comforting and delicious.

It’s not often that an American diner has a chance to eat authentic sticky toffee pudding. King’s version, with clotted cream and “lashings of toffee sauce,’’ is distinguished by the lightness of the date cake (typically dense). King says his is a trade secret, but guests who visit the pub are invited to try to wrangle it from him.

The duo have built up a loyal local clientele at their little spot, which the chef calls “kind of a pub masquerading as a restaurant.’’ But the reach of The Wellington Arms is extensive. “People travel a long way’’ to eat here, says Page.

It’s worth the trip.

The Wellington Arms

Baughurst Road, Baughurst, Hampshire, England, 0118-982-0110, thewellingtonarms.com

Andrea Pyenson can be reached at apyenson@gmail.com.