Peel the beetroot and slice it into thin slices with a vegetable slicer. Marinate beetroot slices with 2 tablespoons of oil and vinegar. Season with salt and pepper. Place slices side by side on 3 baking trays lined with baking paper.
Dry in the preheated oven (fan-assisted oven: 150° C) for 30-45 minutes. Turn 1-2 times.
Heat 2 tablespoons of oil in a frying pan. Fry the sausages for about 10 minutes while turning. Remove and keep warm.
Wash the chives, shake dry and cut into rings. Wash chillies, drain, cut into rings and remove seeds. Grate cheese roughly. Melt the fat in a small pot.
Add the flour and stir until the roux becomes light. Add cream slowly while stirring continuously. Stir in mustard and cheese. Continue stirring at low heat until the cheese has melted.
Cut the sausages into slices. Divide chips and sausage into four plates. Pour cheese sauce over sausage. Garnish with chives and chilli.