How we met: Pierre Gagnaire & Mourad Mazouz

'I planned to ask if he had someone in mind for the venture. He asked, "Why not me?" I freaked out'

Gagnaire (left) says: 'Mourad is an honest man; he is very clear and straight, and we share that mentality' (David Sandison)

Mourad Mazouz, 51

After moving from Algeria to Paris in 1977, restaurateur Mazouz (right in picture) opened his first bistro, Au Bascou, in Paris. Moving to London in 1997, he opened the critically acclaimed Moroccan restaurant Momo, and then the two-Michelin-starred restaurant and event space Sketch in 2005. He lives in London with his wife and two children

My first lunch at Pierre's restaurant in France, several years before we met, almost knocked me out. I was so impressed. He had snail, bacon, mushrooms, beef and foie gras all on the same plate and I thought, "How can someone mix all that together and achieve something that makes sense? It's magical."

Several years later, in 2001, I'd just signed the lease for a building in London [which would become Sketch] without knowing what I would do inside. I asked some chefs I loved who I could go on this journey with, and I set up a meeting with Pierre in Paris. My plan was to ask if he had someone in mind in his kitchen for this venture, but he said, "Why not me?" I freaked out, I had not planned to work with a master. But I said, "That's great!" It felt like a good dynamic and we formed a good connection: I'm North African and at the time he had recently been travelling to Niger, Mali and Algeria, so we talked a lot about that.

He was the first three-starred chef to go bankrupt – with his restaurant in a suburb of Saint-Étienne, a city in deep in recession in the early 1990s. But his restaurant was doing molecular food before anyone else, so for me the story of Sketch, and our friendship, started with his old restaurant. He's told me a few times since, that for him, Sketch is like a revenge: while [the concept] couldn't work in Saint-Étienne, it could in London.

He comes every month to London and I never miss a visit; it's good to see him. But when Pierre is here, service slows down as he changes everything on every plate: he's a perfectionist and each one has to be served differently from the others. I've built Sketch through the idea of constant change, and I love that about him, but sometimes I say, "Pierre we don't have the time!"

He met his second wife, a friend of mine, in Sketch about six years ago. I wasn't sure if I'd be invited to the wedding, but I was delighted to be. I'd like to see him more outside of the restaurant; I'm hoping next June we're going to spend time together with both our wives.

Considering how different we are, I don't know how we built a relationship like a rock. He's from the middle of France, his father was a cook and he grew up in the restaurant business. He works hands-on. But I'm not a chef, I'm a restaurateur, I'm more cerebral. But what connects us is his honesty, and my admiration of him. I sent him a letter recently and ended it with, "I adore you." How you can send a man older than you such a love letter? Because I admire everything about him.

Pierre Gagnaire, 63

The son of restaurant owners, Gagnaire earnt his first two Michelin stars when he took over the kitchen at the family-run Le Clos Fleury in Saint-Étienne in 1976. He won a third star at his eponymous restaurant in Paris. He is also head chef of Sketch in London. He lives in Paris with his wife

Mourad came to see me 14 years ago, in my restaurant. He asked me, "Can you help me to find a chef for my new project, in London?" He explained he wanted to create a place with music, art and different activities, but where food was important. When he explained it to me, I realised it was similar to what I'd wanted to do when I had a restaurant in Saint-Étienne.

So at first for me it felt like a dangerous venture. I said, "We don't come from the same place – he is from Algeria – we don't have the same story." And while he had worked in Paris, too, we had very different clientele: I was always very straight with my food. But I wanted to be part of it.

The problems were big at first. London is not like Paris: people complain. Our builders came from France and they were not accepted by our neighbours: Mourad had big, creative [building-design] ideas so there were a lot of complaints. Sketch was not accepted by the critics at first. Did I worry? Yes, but the real financial risk was with Mourad; when I took the train back to Paris each time, I knew that I would be OK; I was successful with my restaurant in Paris – it was always fully booked. Now everyone knows Sketch because our partnership worked so well. I do what I want with the food and he makes the links between the people and the artists: he is great at creating an atmosphere.

What makes our friendship work? Mourad is an honest man; he is very clear and straight, and we share that mentality. We rarely have time to go out for dinner, though we went to Heston Blumenthal's Fat Duck, which we loved – it's just a different form of theatre to Sketch. I've cooked for him, too; I try to expand his horizons. He said to me. "Pierre, I don't like tripe," and I said, "But you'll like this – try it, it's like magic." And he did.

For me, London is a very important city: it has changed my life. I met my wife in Sketch, she was a passionate regular and it's a real love story. It would never have happened if I had not joined up with Mourad.

Now things are a bit quieter for him, I think he now wants to build deep relationships with the people at Sketch, with the time he now has, including me. But for me, as a chef, if I want to create quality, it's not possible to go out there [to socialise]. My mission in life is to create pleasure on a plate, and to do that I must live in my kitchen.

He wants me to come this summer to have a holiday in Formentera, where I know he likes to go. But we shall see: to me, it's more important that he is confident in my work.

For more: sketch.uk.com; momoresto.com