Peel and wash the sweet potatoes and cut them into sticks. Season with coarse salt and sprinkle with 2 tablespoons of oil. Distribute on a baking tray. In a preheated oven (electric cooker: 225 °C/ circulating air: 200 °C/ gas: see
manufacturer) cook for about 20 minutes. Carefully turn the potatoes in between.
Wash the zucchini and cut into slices. Cut the sausage into slices as well. Put both on skewers. Heat 2 tablespoons of oil in a grill pan and fry the skewers on both sides, turning them over. Season with salt and pepper.
Peel and finely dice the onion and garlic. Wash and coarsely dice the tomatoes. Heat 1 tablespoon of oil in a pot, fry onion and garlic until transparent, sprinkle with sugar and caramelise. Add tomatoes and dust with curry, deglaze with vinegar and orange juice and simmer for 2-3 minutes.
Season with salt and pepper. Puree coarsely with the cutting stick. Take the chips out of the oven, add the skewers and curry sauce.