Sauté the onion, garlic and ginger in the oil. Pour in the apple juice and vinegar, reduce to approx. half the amount. Add the tomatoes, bring to the boil, simmer on a low heat for approx. 30 mins. Add the honey, season, puree and allow to cool.
Using an apple corer, cut a hole lengthwise through the centre of each cervelat sausage. Cut two 2 cm pieces from each stick of sausage. Combine the cheese and diced cucumber. Fill in the hole at one end of each cervelat with a piece of sausage, fill the cervelats with the cheese mixture from the other end, leaving approx. 2 cm free, seal with the remaining sausage pieces. Make several diagonal incisions (approx. 2 mm deep) in each sausage.
Grill: Charcoal/gas/electric grill: Grill the cervelats over/on a medium heat (approx. 200 °C, for approx. 10 mins. all over.
Serve with ketchup.