Fry the bacon in a large sauté pan.
Remove the slices of bacon and place on a plate lined with paper towels to drain.
Once the excess grease has drained, crumble half of the bacon, and chop the remaining two slices into larger, bite-sized pieces.
Set aside.
Make the vinaigrette: Add the shallot to the pan you cooked bacon in, sautéing them over medium-low heat for about 1 minute, until lightly browned.
Pour shallots into a medium bowl, add red wine vinegar, mustard, salt and pepper, whisking to combine.
Whisk in oil, then stir in crumbled bacon.
Set aside.
Fry each egg in the same sauté pan, cooking until the whites are set.
Assemble the salad: In a large bowl, combine spinach, feta, cherry tomatoes and remaining chopped bacon.
Toss with vinaigrette.
Portion salad into two bowls, then top with fried egg.
Serve immediately.
