Anyone scrolling through my Instagram this month could be forgiven for thinking I spend my days gaily dining with abandon at the finest restaurants in London (and Paris) without a care in the world. I've had a pretty great run of meals this January - at Chez Georges in Paris, where I'd wanted to go for years - in London, at Claridges, Spring, The Chiltern Firehouse, Scott's, drinks at Duke's bar, dining at private clubs - all very lahdidah. Appearances are deceptive. Most, if not all of these outings were due to the kindness of family or friends. The before and after of these days was far less glamourous.

So how lucky am I to have all but banished the dreariness of January with good food and company. It's very much a high/low situation: one minute I'm toiling over some extremely mundane task, the next I'm in the glowing surrounds of a truly great restaurant where the surroundings, the staff, the napkins, the cutlery, and most importantly the menu all vibrate at the exactly perfect pitch for me to appreciate and savour.

Spring, at Somerset House, illustrates this perfectly. As my choice for a post-Christmas catch up lunch, I didn't know if it would be too much. Too designed, too showy perhaps. Very hyped restaurants sometimes need time, and quite a bit of it to settle. It is obviously very girly: it's pastel pink, it's baby blue, it's petal strewn. But this didn't seem to faze all the men enjoying their lunch there.

What our lunch at Spring gave me, apart from a very delicious meal in fine company, was the hope of spring in the air. I loved everything about it: the tactile walls in pale blue linen, the touches of pink, the design of the bathrooms and the huge branches of magnolia buds and cherry blossoms that fit the grand scale of the rooms. The sommelier and waiter who looked after us were both knowledgable and friendly - I had heard some sniggering about their uniforms of stripy tops and rolled up trousers, that, it's true, would not look out of place on a fisherman in Pellestrina. But I thought they were perfectly suited to young guys who know about food and wine and are on their feet all day. And then Skye Gyngell in chefs' whites appearing at various points during our meal, in different areas of the restaurant, watching, checking.

My companions both had burrata with agretti (monk's beard) to start, which is just the kind of ingredient I love to see on a menu and then make grand plans to forage. I went straight in for the veal, which was divine, with cavolo nero, borlotti beans, anchovy, lemon and sage. I would eat this happily every day and will try to recreate the beans and cavolo nero part at home. Then a pear, hazelnut and espresso tart. I don't even like dessert much, definitely don't like anything coffee flavoured, but somehow this was demolished in seconds.

It was like a dream. Then back to the reality of train delays, sandwiches in plastic wrappers, too long walks in too high shoes and feeling cold to your core. I'd like to go back soon for another dream.

It was an inauspicious start to the day. I had wanted to stop at Du Pain et des Idées to get pastries for breakfast on the go, but it was pouring with rain and the prospect of hovering next to the canal trying to shelter soggy pastries meant a rethink. We were on our way to see the Garry Winogrand exhibition at Jeu de Paume and decided, since it was raining so heavily, on the easy / whatever option of going somewhere close to it where we could sit down. Le Pain Quotidien was nearby, would have provided a warm and dry refuge (my rubber rain boot was leaking), probably some half decent pastries and coffee, and an unmemorable experience.

Trudging up to the place du Marché Saint-Honoré there was first one, then another cute looking bistro. There are several types of and many deceptively cute looking bistros all over Paris, especially in the very centre: from the faux patina of Costes owned establishments that have been painstakingly distressed to look like they've been there for years, to genuinely old places that look the part, but serve up reheated frozen dishes which have been prepared in an industrial facility somewhere in the suburbs outside Paris. (Read more on this sadly widespread practice here and here.) It's surprisingly hard to find the real deal Parisian dream bistro that hasn't been marred in some way. As Parisians love to say about almost anything; 'It used to be good, but now it's just for the tourists.'

So when we stopped to admire the sign hand painted on the glass door, then peered inside to see a long zinc bar and room of small tables and chairs that could have been from a film set in 1950s Paris, we were intrigued, but didn't expect much. But then my companion pointed out that some of the things written on the menu which hung outside were rarely found on menus in Paris these days. And it just had an air about it. We shrugged and said why not give it a go. It was almost midday so we could go straight in for lunch.

There were only two customers at the bar - the place was otherwise empty. We asked for a table for lunch. 'Premier étage' was the response, as the man nodded towards what looked like a small cupboard door in the corner next to the bar. We looked uncertainly at all the empty tables downstairs - no explanation was given so we opened the door and climbed a narrow, tiny, rickety wooden staircase to the first floor where at the top of the stairs stood a lady brandishing a large knife and an even larger saucisson, which she was peeling. She welcomed us, instructing my companion to leave his umbrella next to the saucisson and showed us into a small dining room, which was also completely empty. The decor was old fashioned, a bit scuffed and faded, but scrupulously clean. I was having visions of a Carry On style farce by this point, what with the saucisson, large knife, umbrella and empty room of little tables and chairs with no exit except back past the saucisson.

We chose a table next to the window and I put my bag on the empty chair next to me, and was immediately politely requested to move it. Although there were wines listed on the wall, the lady just asked us what region we'd like our wine to be from, then rattled off what might suit (and here I must point out how useful it is having a native with you. I would have been a bit lost with the rapid fire French banter and the requisite rapport would have failed to materialise.) We asked for rillettes to start and in short order a huge plate of the best pork rillettes I think I've ever had in Paris appeared, served with bread, cornichons and our wine. The lady stayed with us and chatted - about Paris, about how things used to be, how they've changed, how long she'd been there (27 years), how the rillettes were made by the owner who was from Le Mans, so it was only right that he prepared them.

We ordered our main courses from the choice of around six dishes: saucisson with pommes vapeur and a bit of apple, and jarret de porc with lentilles. Within about fifteen minutes of our arrival the room was elbow to elbow - every table was filled, mostly with men. There were bankers, lawyers, a table of tourists... from another region of France. I was the only non-French person in the room and one of only three women. The lady busied herself in the kitchen and somehow simultaneously and seamlessly seated people and took their drink and food orders, then served them the food she'd cooked herself, without missing a beat.

She gently berated my companion for not eating his onions, which led to me desperately trying to finish the mountain of delicious buttery lentils I'd been served and pleading with him to help me finish the enormous knuckle of pork I'd been trying and mostly failing to demolish. Here is where it became clear why men loved eating here - it was like a return to mother. It was comfort food, food to send sons into battle on a cold winter's day.

We knew we'd return here, so thought it only right to round out our experience with a shared dessert, even though we'd barely be able to walk after the generously portioned main course. We chose a tarte aux poires, but we should have ordered the gâteau au lait, which our hostess had made that morning and was the right choice, we were told. The pear tart was great, but I have no doubt she was right about the gâteau au lait and well, everything.

Of course, later at home with Google, it became clear that this place isn't exactly a secret. David Lebovitz has reviewed it twice! What was special about it for me though, was that with no prior internet research or tip-off, we just physically stumbled on this place in a city we both know very well. We made a snap decision to go inside based on some kind of intuition about its apparent authenticity, which was borne out by our wonderful, memorable lunch there. Trust me, that's a rare gem indeed.

Le Rubis, 10 rue du Marché Saint-Honoré, 75001, Paris.

C/O JOURNAL