While I love bacon dressing, my husband isn’t a fan and our vegetarian friends can’t partake, so I wanted to make an equally delectable warm vinaigrette to toss with an easy spinach salad. The result of using brown butter instead of bacon fat is a salad that’s worth making again and again. For this quick side dish, I kept the classic spinach salad as the base because it holds up so well to the temperature of the dressing.