In a large mixing bowl, toss the baby spinach, crumbled bacon, thinly sliced red onion, hard boiled egg slices and crumbled blue cheese.
In a resealable glass container, add 3 Tbsp warm bacon drippings with the sugar, spicy or Dijon mustard, red wine vinegar, Tarragon oil and a pinch of salt and pepper. Shake vigorously and taste. Add 1 more drop of Tarragon, if desired.
Pour the Tarragon Vinaigrette over the salad.
Serve Spinach & Bacon Salad with Homemade Tarragon Vinaigrette for lunch or as side salad with dinner.