If you, like me, are a regular chicken roaster, you're halfway to one of the best salad dressings out there: schmaltz vinaigrette, a tangy, savory top coat for a simple salad of mixed greens and whatever you've picked up at the farmers market.

Using a warm fat, like bacon or duck fat, in a vinaigrette is a time-honored practice that works extremely well thanks to the ability of fat to emulsify with the other ingredients, creating a silky, rich dressing. Warm bacon dressing over a spinach salad is a classic for a reason, but I would argue that a good schmaltz vinaigrette is even better.

While m...