Make the dressing: In a skillet whisk together bacon drippings with browned bits, olive oil, red wine vinegar, dijon and honey. Season with salt and pepper to taste. Allow to simmer over medium heat 1 minute. Stir in 2 slices crumbled bacon. Allow to cool slightly.
Assemble the salad: In a large salad bowl, toss together spinach, remaining bacon, mushrooms, red onion and swiss. Drizzle with warm dressing and toss. Add eggs and croutons to top and serve.
Notes
Use bacon that isn't flavored for the best results. You just want a regular pork bacon for this recipe.
Store the dressing and salad fixings separately in the fridge if you have leftovers. Otherwise the salad will wilt.