I tried this the other day, in a restaurant. I felt a little goofy. But also happy. My bread that day was a croissant, so naturally, it smiled back at me.
As my bread and I smiled at one another, I remembered the gist of what Thich Nhat Hanh had said: "The piece of bread is an ambassador of the cosmos, offering nourishment and support. Looking deeply into the piece of bread, I see the sunshine, the clouds, the great earth. Without the sunshine, no wheat can grow. Without the clouds, there is no rain for the wheat to grow. Without the great earth, nothing can grow. That is why the piece of bread that I hold in my hand is a wonder of life. It is there for all of us. We have to be there for it."
He proposes: "Eat with gratitude. And when you put the piece of bread into your mouth, chew only your bread and not your projects, worries, fears, or anger. This is the practice of mindfulness. You chew mindfully and you know that you are chewing the bread, the wonderful nourishment of life. This brings you freedom and joy."
The Pocket Thich Nhat Hanh, pages 32-33.