Finely mince the onions (or grate), and combine the ◆ ingredients.
Dry fry the ◎ spices in a frying pan until fragrant. Transfer a teaspoon worth in a separate bowl for the end.
Sweat the onions with olive oil, then add the spices from Step 2.
Lower the heat, add the ◆ ingredients and stir to prevent scorching. Stop the heat once it bubbles and let rest for an hour.
Roast the sausages, plate, then spoon over the sauce. Sprinkle with the reserved spices and it's done.
If you make a large batch of the sauce, it will keep in the fridge for up to a week.
Story Behind this Recipe
I wanted to make currywurst at home, so I consulted various German recipes sites and cookbooks, and tried out various food stands.
I was surprised that many recipes call for soy sauce!
The sauce differs by region; some have onions, others do not. Some call for parsley. There are also variations on the way the sausages are cut. You can slice the sausage into rounds or serve it whole with the sauce.