I have several suggestions for you; alas, none is on a canal. For lunch on a busy day of sightseeing, try the amazing restaurant level at La Place department store, downtown. For a nice dinner, I have three suggestions. Two, Wave and Zorba de Griek are on Restaurant Row, an unabashedly touristy area, but the food at these two is great. Wave is at Lange Leidse Dwarsstraat #27. Great seafood, with some of the best fish I have ever eaten. Zorba de Griek is in the same street, but I don't know the number. Probably the best rice and the best lamb I have ever had, anywhere. And huge portions, with attentive service. And near the Hotel Alexander is the Italian restaurant Sogno, at Stadhouderskade 7. Very good food, and outstanding cappucino. One more: our group "Last Supper" was at the Cafe Americain: an incredible meal (the prawns!) at what would have been a major splurge had it not been included on our tour. We had never thought of Amsterdam as a "restaurant city," but we never had a bad meal, and had several remarkable ones.