Only way I can think of is using a slice of low pp bread and cut it to cubes and fry in frylight with a bit of seasoning (maybe some garlic would be nice too!). You could probably get away with only using half a slice of bread
i brought some tesco finest olive oil and sea salt crostini's 10g is 1pp, 25g is 3pp ..... to be honest 10g would probably be enough as a something for your soup or salad
....... and they are not hard little cubes like croutons!