Preheat oven. Place torn pieces of bread on a rimmed baking sheet, then toss with olive oil and Kosher salt. Bake until crispy and golden brown. Set aside until needed.
Cut sliced bacon into matchsticks.
Heat a medium skillet over medium heat. When hot, add the lardons and cook until crispy on all sides, stirring occasionally. Use a slotted spoon to transfer the cooked bacon to a paper towel lined bowl.
Return the skillet to medium heat, then add minced shallot and cook until soft. Add red wine vinegar and Dijon mustard, then whisk. Set aside until ready to serve.
Fill a medium saucepan with water. Bring to a boil, then reduce the heat to medium-low. Add white vinegar, then swirl the water into a whirlpool with a spoon or spatula. Carefully drop in one egg, then let it set. Cook until the whites are cooked through.
Place frisée leaves in a large mixing bowl, then add the lardons. Drizzle the hot bacon dressing on top,then give it a good toss. Season to taste with Kosher salt and black pepper. Divide the salad. Serve immediately with a drizzle of extra virgin olive oil and a pinch of flaky sea salt.