Heat the olive oil over medium high heat in the skillet until very hot. Add the pancetta and cook, stirring occasionally until crisp and has rendered its fat. Transfer the pancetta to a small dish lined with paper towels to drain.
Place the sauerkraut in a strainer and rinse well with cold running water. Lightly press on the sauerkraut to force out any excess liquid. Set aside.
Carefully place the bratwurst into the hot skillet and cook for 3-5 minutes, flipping occasionally until the sausages are browned (they don't have to be fully cooked yet, because they're going back in the pan to simmer). Transfer the sausage to a sheet pan.
Add the onions and potatoes to the pan. Season with salt and pepper and cook for 4-6 minutes until the onions soften and the mixture is fragrant. Add the apples, caraway seed, sauerkraut, white wine and chicken broth. Stir to combine.
Transfer the sausages back to the skillet and nestle them into the sauerkraut mixture. Bring to a boil, then reduce heat to a simmer. Cover and cook for 15 minutes.
Serve with pommery mustard. Great with a crusty piece of bread, European butter or a semi soft cheese like Port Salut or Chaumes and chilled (Alsatian) white wine.