Cook the bacon pieces in a large skillet over medium-high heat until crisp; transfer to a paper towel-lined plate to drain. Add the shallots to the pan and cook until softened, 2 to 3 minutes. Pour in 2 tablespoons vinegar, reduce the heat and simmer gently for 1 minute.
In a large skillet, bring about 6 cups of water and 1 tablespoon of vinegar to gentle simmer. Crack the eggs, 1 at a time, and gently slip them it into the water. Cook until white is set but yolk is still runny, about 1 1/2 to 2 minutes.
Add the frisee and crisp bacon pieces to the warm pan dressing, season with salt and pepper, to taste, and toss to coat. Divide the dressed frisee and bacon between 4 plates; top with a poached egg and season with salt and pepper, to taste. Serve immediately.