Mix deep-frozen blueberries with jam sugar in a pot. Cut the vanilla pod lengthwise and scrape the pulp out of the pod to form the blueberries. Add the vanilla beans as well. Rinse the chilli peppers, cut lengthwise and add.
Cook jam according to package instructions and fill into jars (remove chilli and vanilla pods!).
Peel the sweet potatoes and cut into very thin slices. Heat the oil to 175°C. Fry the sweet potatoes in it in portions and let them drip off on kitchen paper.
Chop the walnuts very finely. Mix yoghurt with jam and walnuts. Season with a pinch of salt. Serve the dip with the sweet potato chips.