Olivier is obsessed with sugar; he said so himself. I’m with him at L’Etranger, the Sofia restaurant that he created more than eight years ago, and he is using some sort of wire whisk with sugar-coated tentacles to create nests of spun sugar from a saucepan of dark caramelisation: cheveux d’ange (angel’s hair).

He says his interest in sugar started in his first job, when he was a lad of 16 living in his native France. The traiteur (French delicatessen) where he was a shop assistant had an order for a Harley-Davidson to be made completely of sugar, and something about that experience has stuck with him to this day.

Olivier opened L’Etranger after moving to Bulgaria with his Bulgarian wife, and, not having found satisfaction at a comfortable desk job, went on to what inspired him – cooking. Its first two years were on Assen Zlatarov Street, in the Doctors’ Garden neighbourhood. He moved it to its current location on Tsar Simeon Street after the landlord raised the rent exponentially.

The intimate facility he now occupies seats about 38, though it can squeeze in up to 80 people for a buffet – like he has for the annual release of Beaujolais Nouveau’s new vintage. Olivier – and until 18 months ago when he hired an evening assistant/line cook, he had always worked solo – occupies a small giraffe-shaped improvised kitchen in the basement.

"Until about two years ago, I had never let anyone enter my kitchen," he says. "My kitchen is mine, my lair." In this space, he prepares everything himself, from the roti de porc to the creme caramel to the gesiers confits to the vegetable purees and sauces, all according to the French traditions that he learned in cooking for his siblings from the age of 12, and from working in the traiteur, followed by experimentation, self-education and constant reading of French culinary industry journals.

Stacks of the magazines, going back a number of years, sit on the bookshelf outside the kitchen. He reads them more for inspiration than for specific new menu items. Next to them sit Le Guide Culinare by Escoffier ("useless, unless you already know everything about cooking and technique") and Petit Larousse de la Cuisine ("this is the good one").

We sit at a table downstairs and talk for a bit in the mid-afternoon lull. What really set Olivier off at the beginning was how he would work to prepare a dish, have everything at the correct temperature, exquisite presentation, and deliver it to the customer... who would then light up a cigarette and push the dish aside for 10 or 15 minutes, the food getting cold and coagulated. Since then, he has learnt to adapt to the Bulgarian mentality, and the customers themselves have become more "educated" about fine cuisine.

In our conversation, he conveys a sense of high ideology, the expectation of beauty and finesse and passion as related to food and dining. This, perhaps, is part of why France is lauded for its kitchens  and restaurant experiences. And there is another layer that peeks out: that of melancholy as a result of idealisation disappointed. But that is life, and he makes the best of it. He searches out small suppliers that appreciate and maintain certain standards of quality. He buys local when possible. His cooking is clean, thought out, accessible.

"It’s not hard to find the products. What is hard is to find them again – one day it’s there, the next day it’s gone forever," he says. And then there is the fact that his cooking is French. In a society that has traditional tastes and is often fearful of something that does not look "typical", certain foods have been a hard sell. Creme brulee a la lavande (lavander) when he first started making it, was a novelty.

People did not know what it was, so he would end up serving it to the customers gratuit. Now, it’s everywhere – the ‘normal’ variety of creme brulee at least. His next provocation is the avocado-chocolate souffle. The  avocado lends a distinctive green colour, a mildly riddling taste and a certain depth, while the melted chocolate chunk in the centre complements the sweetened complexity. Diners were unnerved. Olivier has not been dissuaded.