The Mussel and Steak Bar is something of an Edinburgh Old Town institution. Even if you’ve never been inside, you’ll recognise its turquoise front if you walk to the bottom of the cobbled Victoria Street, and follow the curve round onto West Bow. This year, the well kent business celebrated its 20th birthday. Its longevity might be down to its excellent location. Or, sticking to a simple formula that works. We spoke to its owner, Marshall Milne, about the restaurant’s continued success. How does it feel to be celebrating 20 years? I can’t quite believe I’m 20 years older! It’s been spectacular, I’ve had an amazing time here and The Mussel and Steak Bar just keeps getting better. It’s quite a landmark. What is your secret? From day one, consistency. We started out with the name, what we are called is what we do. The ethos has always been Scottish seafood and steak and from there we’ve developed some other dishes for variety, but we’ve always kept top quality from our suppliers. Our consistency has meant that people have come here 10, 15 or even 19 years later and can’t believe we’re still here. They can’t believe the quality of the food is still the same from their first visits. That really makes me feel very proud that our staff here give such excellent service and the chefs do a wonderful job. Is there anything you wish you'd known before starting the business? I’ve always been somewhat of an adventurous person and decided I wanted to open a seafood and steak restaurant without too much thought. With my farming background I already had contacts with suppliers for seafood and beef so it was quite easy for me to source top quality products. What have been the high and low points over the last two decades? Looking back always brings a smile to my face and, yes, there have been challenging moments but the highs outweigh the lows. One of the biggest highs for me is not knowing what each new day brings, who will visit the restaurant and what conversations you may have with customers, staff or suppliers. I’ve met and become friends with people from all over the world. I’ve met them in their own countries of Canada, Europe and cities like New York after they’ve visited the restaurant and shared some of their own life in their own countries. I’ve particularly built a huge network of friends who live in mainland China and have visited the country and cities many times. It led to The Mussel & Steak Bar being represented for St Andrews Day in Beijing, including hosting a 400 person dinner. I’ve had many wonderful nights and met wonderful people there. As part of my visit last year, I was encouraged to have a full body health check. They discovered a tumour. I received treatment there but what was significant to me was how quickly they were able to identify, diagnose, begin treatment and perform the operation I required. The treatment I had was absolutely second to none. I would recommend that people go to Shanghai, China as it’s a spectacular metropolitan city for a holiday and also have a full body health check. Who have been the most interesting customers you've had. Any celebrities? The most interesting customers we’ve had through the restaurant since opening, and there have been many thousands, have been the everyday public. I’m not really interested in celebrities, though we’ve had many A-list Hollywood people, producers, music people over the years and many of them return time again because we treat everybody the same. It doesn’t matter who you are or where you come from, the ethos is to give the best service and best quality food at all times. Each customer is special to us, we never give special treatment to anyone over anyone else. Have any small changes been made to the menu, or does it remain exactly the same? Our core menu of dishes has remained of steak, mussels and seafood throughout the years. Driving through the Rockies in Canada is when I came up with the name The Mussel and Steak Bar, so that people knew what they were going to get before they’d even walked through the door. As tastes have changed, we’ve added some new dishes which have proved popular, but we haven’t changed the base menu. Where do you source your produce? All of our key ingredients have come from Scottish suppliers and a lot from the Western Isles in particular. We consistently source Shetland mussels, oysters from Orkney, lobster, king scallops, langoustines and crabs from the West Coast. The beef is from the Central Belt of Scotland. Some people who have supplied us in the past have unfortunately ceased trading or moved on. However, we still work with a number of the same suppliers and even some of the same staff in the restaurant who started with me 20 years ago which is really quite incredible. What's it like being at the bottom of one of Edinburgh's most Instagrammed streets? When we originally looked at different areas to open the restaurant 22 years ago, I wanted to be somewhere interesting and exciting. The Grassmarket is somewhere that I really liked and it’s always been an exciting place to be, but 20 years ago it wasn’t as much of a draw for tourists. That has changed and now it’s a key area for visitors to Edinburgh, which makes everyday interesting and fun as you never know who will visit. I really love it here. Is the Old Town a friendly neighbourhood to work in? The Old Town is a friendly and open-minded neighbourhood. Grassmarket has always been appealing to me as you always meet some wonderful characters. One business that comes to mind is Clarkson of Edinburgh Jewellers up the road. Mr Clarkson senior opened in 1958, his two sons now run the business and they are probably the oldest independent family retailers. There are some other wonderful establishments down here also, some have changed and some have been here before me but they’re a very warm and welcoming community. The Mussel and Steak Bar, 110 West Bow, Edinburgh (0131-225 5028, www.musselandsteak.com) Read more: “The Edinburgh family deli that’s still Scotland’s best after 90 years in business”