Heat oven to 480°F (250°C).
In a frying pan add bacon (or any cured meats with fat on it), and heat up on medium, occasionally stirring. When the meat starts to warm up and/or melt, add onion. (If the pan is dry, add 1-2 tablespoons of oil as well.)
Fry everything an additional 4-5 minutes, or until the onion starts to sweat. Stir occasionally. (The meat should not be completely fried!) Transfer to the baking pan.
Try the sauerkraut. If it's too salty for your taste, wash it in lukewarm water. Drain and slice thinly. (Even if it is shredded, slice it a little bit thinner.)
Add sauerkraut and seasonings to the baking pan. Add any meat rinds, or remaining cured meat as well. Mix all the ingredients really well. (If making this as the main course, place the big pieces of meat on top, after you mix everything.) Add 1-2 glasses of water to the pan.
Cover the pan with foil, and pierce several small holes for the steam to get out. Lower the heat to 400°F (200°C), and transfer the pan to the oven. Bake for 90 minutes.*
About 60 minutes into the baking, take the pan out of the oven. Carefully lift the foil away from yourself, and check the fluid level. If it's running low, add a little more water. Fasten the foil again, and return to the oven for the remainder of the time.
After 90 minutes in total, lower the temperature to 300°F (150°C), and take the foil off. Bake without foil for an additional 15 minutes.*
Serve: warm to hot by itself or as a side like polenta, rice, mashed potatoes, homemade bread. (Remove meat rinds before serving.) Store: in an airtight container (or foil) in the fridge or a very cool balcony for up to 2-3 days. Freeze for up to 2-3 months. Take out a few hours before you plan to eat it. Let it thaw and then reheat. Add fluid/ water as necessary. Reheat based on your preference. We recommend reheating it on the stovetop, on the lowest setting.