When she was a child, the part-Vietnamese, part-French and part-Chinese entrepreneur ate mainly Vietnamese and French food. But she appreciates the family-style Chinese cuisine on offer at the Bayswater restaurant.
"It's the only restaurant in the world I can go to on my own," she says. Actually, she adds, she hates eating on her own, but she makes the point to emphasise how much like a second home the restaurant has become for her and how comfortable she feels there.
"I know the manager so well, and he knows me so well, that I can say I don't want anything on the menu, I want something family-style - meat or fish, vegetables and soup in the middle, the sort of food they will cook for the waiters and waitresses."
However, her tastes do go some way beyond the simple and straightforward. She loves lobster and, as she admits she "only eats nice things", she rarely sees any change from pounds 100 for a meal for two, not including drinks.
The restaurant is dark inside, with lots of glass - a little like a spaceship, says Wuillamie. She enjoys taking evening meals there and finds it suitable for quick, weekday business lunches too.
"All my business associates can eat with chopsticks," she says. "I always ask if they want a knife and fork, but they get terribly offended. The people we deal with are very sophisticated, City people."
As well as CWB, Wuillamie, a finalist in this year's Veuve Cliquot Business Woman of the Year awards, has also founded a champagne import company, and she keeps her own private reserve of champagne at the Royal China. The restaurant doesn't charge her corkage for the special privilege.
Royal China, 13 Queensway, London W2 (0171-221 2535)