I don't have a "tried and true" recipe as when I make this I usually just throw it together. Here's what I do; mince 1 onion and a clove of garlic, sweat in butter until translucent then add some curry powder (yes the yellow stuff-sweet or hot, your choice I use either or both depending on my mood). Cook a minute or 2 stirring constantly. Deglaze with a bit of worcestershire sauce and an ounce or 2 of the beer you're drinking then add about 2 cups of ketchup. Simmer for 10-15 minutes, over low heat and serve over sliced sausages.
It's not fancy and when I first heard of this I thought it was bizzare, but I've come to really like it. Not sure how "traditional" my version is, but it is tasty.