Shred the cabbage, grate the carrot and chop the onion. Combine in a large bowl.
In the bowl of your food processor, chop the bread & butter pickles. Add the yogurt and olive oil and pulse until combine. (Or chop the bread & butter pickles by hand and mix in a small bowl with the yogurt and olive oil.) Stir the dressing into the coleslaw. Season to taste with sea salt, fresh pepper and a touch of sugar if needed.