Pound the beef slices well and thin them to about half of original thickness. Sprinkle with salt, then with flour on both sides.
Heat lard in a frying pan and brown meat on both sides over high heat for a few minutes. Remove meat and put aside.
Cut onion into rough pieces and wilt it in the same fat over low heat for about 15 minutes. Add crushed garlic, caraway seeds and paprika. Stir the mixture and add 2cups cold water.
Place beef slices in a single layer in the same pan. Cover the pan and cook over very low heat. If you use low heat and a heavy cast-iron pan with a tight-fitting lid, you probably will not have to add any more water. If the sauce thickens too much, add a small amount of water to prevent burning.
When beef begins to soften, add diced potatoes, green pepper and tomato, and enough water to barely cover potatoes. Cover the pan and cook over very low heat until the meat is done.