• Wash sauerkraut under cold running water then soak in cold water for 20 minutes to reduce sourness. Strain well, pressing out excess water.
• Note: I am a big fan of searing meat, because I think it gives sauces a deeper flavor. While the original recipe didn't say to do this-- I plan to sear the pork in some olive oil and then to continue with cooking the onion and garlic and carrying on with the rest of the steps.
• Melt butter in a 5-quart casserole; add the onions. Cook over medium heat, stirring occasionally until lightly colored, 6 to 8 minutes.
• Add the garlic, season with salt and cook a minute or two longer.
• Stir in paprika, pour in 1/2 cup of broth and bring to boil.
• Add the pork cubes. Spread sauerkraut over pork sprinkle with caraway seeds. Combine tomato puree, tomato paste and reserved broth, in a small bowl. Mix well and pour over sauerkraut. Bring to a boil.

If using a slow cooker:

• If using a slow cooker, transfer contents of casserole to slow cooker insert. Cover, and cook on high, for 4-6 hours, or until pork is fork tender but still retains its shape.

If using a conventional oven:

• If using a conventional oven, preheat to 250°F. Cover casserole and transfer to the oven. Cook, covered, for 3 to 3 1/2 hours, or until pork cubes are tender but still retain their shape.

To serve:

• When the pork is tender, transfer meat and sauerkraut to a serving platter with high sides. Tent with foil to keep warm.
• Transfer the sauce to a 2-quart pan. Set over medium heat. Combine flour, heavy cream and sour cream in a small bowl. Whisk until smooth. Stir mixture into sauce and simmer for 10 minutes longer. Do not boil.
• Season to taste with salt and pepper. Pour over meat and serve. Pass additional sour cream as a side.