this puree garnish looks great and tastes very interesting.
it can be served as a vegetarian menu or complement steaks with different sauces.
if you cannot find blue potatoes you can substitute them with sweet potatoes, carrots or peas.
boil the 2 types of potatoes separately.
from the classic potatoes make a puree (with sour cream, some butter and salt or soy cream - for a vegetarian pure preparation).
chop the blue potatoes into cubes and mix with the puree.
serve hot with salad or pickles.
enjoy your meal!