Peel and finely dice the onions. Finely dice the cucumbers. Heat butter in a pot. Fry onions until translucent. Sprinkle with sugar and melt. Sprinkle with 1 tbsp curry and sauté briefly.
Add the chopped tomatoes, ketchup and cucumber. Bring to the boil and simmer covered for about 10 minutes. Season to taste with salt, pepper and vinegar.
Heat 1.5 l of oil in a wide pot or in a deep fryer to approx. 180 °C (it is hot enough if bubbles rise from a wooden skewer) Fry the chips in it in 4 portions until golden brown.
Remove the finished chips with a skimmer and let them drip off briefly on kitchen paper. Season with salt.
Cut the sausages into slices and heat them in the sauce. Season sausage goulash with salt, pepper and curry. Serve with chips.