Sauté onion in bacon fat. Stir in broth, beer, sauerkraut, tomatoes, brown sugar and red pepper flakes. Bring to boil and simmer, uncovered, for 1 hour.
Add sausage and potatoes. Cover and cook 30 minutes, or until potatoes are tender.
Vegetable oil or olive oil can be used instead of bacon fat.
Submitted by: jenny clifford