One of the hard-and-fast rules about dining out, alongside never trying to eat the hot towel or order the wine called “Corkage” because it seems the most reasonably priced, is never to get the chef talking about sustainability. Never. For many, you see, it’s their obsession, and at The Loch & The Tyne in Old Windsor, before you know it, you could be perusing the eco-garden and composting area on a Vélosophy bike made out of recycled Nespresso pods. That said, The Loch & The Tyne is an Adam Handling venture, run by his trusted, longstanding cohorts Steven Kerr and Jonathan McNeil, so if you were to break that rule, this is the place to do it. Over the past decade or so, Handling has become a leading light in reusing, replanting and giving a damn about the polar bears via The Frog in Covent Garden and the now defunct Ugly Butterfly in Chelsea, which was recently reborn in Carbis Bay, Cornwall. Handling and his team catered at the G7 summit in June, offering Macron and Merkel treats made from offcuts and local produce, although I’m certain they’d never have known how saintly it all was unless they had been expressly told. Handling’s approach to food waste has always been delicious, luxurious and playful, but if I told you one of my favourite things at The Loch & The Tyne was a large, crisp potato scone covered generously in melted, pungent beauvale blue cheese and crisp onions, which I ate with a bright orange, north of the border twist on the porn star martini made with Irn-Bru, perhaps you’ll notice that we’re a long way from worthy. His formative years at Gleneagles hotel in Auchterarder are alive in such moments, while elsewhere on the menu there is Balmoral chicken and a posh fish and chips with tartare and curry sauces. My visit to Old Windsor was on a Saturday full of chores, suddenly rerouted by hunger. We were on the M25, somewhere between Staines and Heathrow, collecting a car from a garage – faulty central locking, since you ask, though I won’t bore you – when I remembered talk about Handling’s latest brainwave, a “traditional British pub” that serves tarts, souffles and gingerbread trifle in a leafy setting down some lane in Windsor where the Michelin-starred gastropub The Oxford Blue once lived. It’s a spacious, modern country pub with a large outdoor terrace, oversized parasols, tartan blankets and a beer garden with a fire pit. Indoors, it’s all exposed brickwork, comfy leather chairs and mahogany tables. The whole effect is calm, elegant and slightly dreamy: the kind of pub you take an overseas tourist to, to give them the sort of bucolic British vibe they’ve only ever seen when author/murder magnet Jessica Fletcher goes home to Blighty for a book tour. I have a rule of thumb when reviewing restaurants that you can tell “a good one” by how soon you begin subliminally planning to come back, which in this case was inside 12 minutes, when warm sourdough appeared with chicken butter topped with crunchy, fatty bullets of chicken “crackling”, followed by the aformentioned tatty scone – which one rarely sees on a menu this far south – and a light, crisp, beautifully seasoned lobster tart. We rampaged across the small plates because it was a balmy summer’s day, so sitting on a terrace eating a 300g ribeye with bone marrow seemed just a touch ambitious. Also, I wanted to try the twice-baked cheese souffle, a delicious if slightly sturdy affair served with pickles, and neither could we miss out on an oddly named dish called “Mother”, which remains one of the most eccentric things I’ve ever eaten. It turned out to be a peculiar, almost unnerving, alien-like mass of wafer-thin celeriac and apple arranged around moist black dates and some sort of soft cheese, and covered in a generous shower of black truffle. “I am not sure if I am enjoying this,” I said while lifting spoon after spoon to my confused mouth. I had to eat Mother before she ate me. By this point, I’d had two glasses of Handling’s own very good English sparkling wine, and was very much at the “Damn it, let’s stay the night and have dinner, too” point of the afternoon. And that, surely, is the point of lovely lunches: they make you want to abandon reality and set up home. I am more grateful than ever right now, when so much of hospitality is working poorly, when teams such as Handling’s just quietly get things done. For pudding, we had strawberry trifle, which came in a pretty, short-stemmed pudding bowl. It was all the colours a trifle should be – red then yellow then white – so I will accept the scattering of edible petals. The fruit and jelly layer featured chunks of gingerbread, which were odd, but unforgettable. The Loch & The Tyne is a secretly Scottish, discreetly eco-warrior, elegant but casual fine dining restaurant hiding in a pub down a back lane in Berkshire. Saving the Earth has never been so much fun. The Loch & The Tyne 10 Crimp Hill, Old Windsor, Berkshire, 01753 851470. Open Wed-Fri, noon-3pm, 5-10pm; Sat, noon-10pm; Sun, noon-7pm. About £50 a head à la carte, plus drinks and service. Grace’s Comfort Eating podcast is out now. New episodes are released every Tuesday.