The most tempting food for canaries are foods that are white. Even the most finicky eaters will enjoy munching Soft white bread. I have tried whole wheat and mine just look at it. If it is dry, they lose interest in it. Soft white bread right out of the package is promptly eaten.
It is a great way to tame them and make them love their show cage. I can cut the size down and move it up to top to encourage this Border to stretch.
The most tempting time to feed a new food is first thing in the morning. Even with seed mix in the cages they wait and wonder "What's For Breakfast?"
My husband says "Hunger is a great sauce!"