Lardons were originally used to add fat and richness to lean cuts of meat before roasting or braising. Cut into thin matchsticks, the lardons could be inserted right into the meat itself. Appropriately enough, this process is called larding!
Along the way, someone realized that these little lardons (or lardoons) were quite tasty when cooked until much of the fat is rendered out. Think chewy bacon meets pork rinds. Since they're more fat than meat, lardons have a slightly a different flavor and texture from bacon. There's still enough similarity between the two that they're frequently used interchangeably. (You'll often see recipes refer to bacon lardons, meaning lardons cut from slab or thick-cut bacon.)
Cooked lardons are an excellent addition to salads of fresh greens. One classic French bistro specialty combines lardons with frisée greens and a poached egg. We actually love pairing lardons and egg, and think lardons are great in other egg dishes like quiches and frittatas.
Lardons can also be used like bacon to add a flavor base to soups and braises. Cook the lardons over medium heat until most of the fat has rendered out and then remove the cooked lardons with a slotted spoon. Use the rendered fat to cook the rest of the ingredients and then add the cooked lardons back in at the end.
Are you a fan of lardons?