Julienne the white cabbage and the 2 carrots using a mandoline, so you have fine, even, strips. Place in a large bowl.
½ large white cabbage, 2 medium carrots
Carefully grate (shred) the quarter of an onion using a grater and add the onion to the bowl.
¼ brown onion
Add the cup (240g) of mayonnaise, 3 tbsp sour cream, 1 tbsp white wine vinegar, ½ tsp salt, 2 tsp sugar, ⅛ tsp mustard powder and the pinch of white pepper.
240 g (1 cup) mayonnaise, 3 tbsp sour cream, 1 tbsp white wine vinegar, ½ tsp salt, 2 tsp sugar, ⅛ tsp mustard powder, pinch white pepper
Stir everything together until thoroughly combined.
Serve immediately, or cover and refrigerate until needed (up to 2-3 days).
Notes
Adjusting the quantity of coleslaw
You can increase or decrease the amount of coleslaw by adjusting the ingredients proportionately. If you're just looking to make a small amount of dressing - for example you want to make one cup of coleslaw, use: A matchbox-sized piece of cabbage, ¼ of a carrot, a tsp of grated onion, 2 tbsp mayo, 1.5 tsp sour cream, a few drops of white wine vinegar, a pinch of salt, ¼ tsp sugar and a tiny pinch each of mustard powder and white pepper.