We do use real bacon in this recipe, but very little bacon fat.
Fry the bacon over medium-high heat in saute pan until crispy, pouring off the fat often. Reserve 2 tablespoons of the fat.
Pat the cooked bacon dry with paper towels and remove all the fat by hand. Break or chop the remaining lean bacon meat, all visible fat removed, into 2,5cm long pieces (if the bacon is already cooked, scissor off the visible fat).
In a small bowl, add the vinegar, oil, sugar, mustard, and reserved 2 teaspoons bacon grease and mix well.
Place the spinach in a salad bowl, add the bacon and onion slices, pour on the dressing, and toss. Add salt and pepper to taste. Garnish with olives.
For variety add 200ml can drained mandarin oranges, 1/2 cup crumbled feta cheese, a handful of sunflower seedsor slivered hard cooked egg and croutons.