ive never made it before this is what ive got ive got two leeks, potatoes, 1 onion, 2 veg stock cubes a carrot would i need that? salt and pepper, milk to i add that to make it creamy. Is that the correct ingrediets-would you add a carrot? And do i just blitz it all at the end.Basically what do i need and how do i make it?