Soak the pretzel rolls in the light beer for about 5 minutes until softened, then squeeze out the excess liquid.
Peel and dice the onion, dividing it into two portions.
In a large bowl, knead together the minced meat, squeezed rolls, eggs, mustard, and one portion of diced onion. Season with salt and pepper. Sprinkle breadcrumbs on a baking pan to coat the bottom. Press the meat mixture firmly onto the breadcrumb layer.
Bake at 175°C (347°F) for about 25 minutes.
While the meat bakes, cut the smoked bacon into small pieces and fry over medium-high heat until crispy, about 5 to 8 minutes. Remove and drain. In the same pan with the bacon fat, sauté the remaining onion over medium heat for about 2 to 3 minutes until softened.
Clean, wash, and dice the red peppers. Drain the sauerkraut to remove excess liquid. Add the peppers and sauerkraut to the pan with the onions, return the bacon, and stew for about 12 minutes over medium heat. Season with salt, pepper, and paprika powder to taste.
Remove the meat from the oven and spread the vegetable and bacon mixture over the top.
Grate the Gouda cheese and mix with the sour cream. Season with salt and pepper. Spread the cheese and sour cream mixture over the vegetables and bake for another 20 to 25 minutes at 175°C (347°F) until the top is golden.