Haskins chairman Warren Haskins and chief executive Julian Winfield joined the VIPs on a tour of the new facilities completed after the seven month construction.
The 460 seat restaurant includes a stone hearth pizza oven, a daily carvery, Costa coffee, free Wi-Fi, two patio areas, a children’s play area and extendable function room.
"We are grateful to the Mayor and Mayoress for performing the opening of the restaurant that is not only double the size of the original restaurant built in 1996, but now employs a total of 82 catering personnel including eight full time chefs.
"We know that the restaurant will become a destination for anyone who wants a great choice of menu and a superb standard of service within a modern, clean friendly environment."
The Mayor said: "The new restaurant will certainly encourage people from across the region to visit West End and will provide a boost to the local economy."
The company’s sister garden centre at Longham, Dorset opened a new restaurant with similar menus, features and layout in 2008 where the catering turnover has increased from £1.2m to £2m per annum.