When I worked for Georges Perrier at Le Bec-Fin, they put raw onion in the sourdough, a practice that is quite common in France. I didn’t like the sharp, acrid taste at all, so Georges showed me how to get serious about caramelizing onions. His method takes a long time and a lot of stirring, but it’s so much better than the common shortcut of adding sugar to onions and sautéing them. I incorporated those onions into a baguette, which Georges liked a lot. Here’s the secret: The onion should be neither the centerpiece nor the last thing you taste; instead, it should be a persistent note in a chorus of flavors. For this recipe, I thought the fresh and slightly cooling sensation of buckwheat would play well with the other ingredients. I also used butter because it works well with caramelized onions, and honey, to extend the sweet finish the onions elicit. Georges would serve this bread with smoked meat, especially bacon or pancetta. I love it with brisket or anything you’d serve with caramelized onions. If you make traditional French onion soup, it would be an ideal crouton.