1.Preheat the oven to 200°C/180°C (fan)/390°F/gas mark 6. Put a large baking tray in the oven to heat up (this will stop the flat bread bottoms from going soggy!)
2.Prepare the cucumber salad: thinly slice the cucumber, and finely chop the dill. Place in a bowl with the salt, sugar and white vinegar. Mix thoroughly and set aside to allow the flavours to develop and cucumbers to soften.
3.Peel and finely dice the onion and remove the sausages from their casings. Discard the casings.
4.Heat oil over medium–high heat; sauté onion until tender, 1–2 minutes. Add the sausage meat and sauté until lightly browned, 6–8 minutes.
5.Spread half the creme fraiche mixture over each flat bread, top with the sausages and onions and place on the hot baking tray in the oven for 8–10 minutes.
6.Remove the flat bread pizzas from the oven, top with sauerkraut.
