Like onions, leeks develop a rich, savory flavor when cooked slowly. And when cooked this way, they make an excellent addition to a creamy mound of mashed potatoes.
Rather than caramelize the leeks, which requires a bit more hands on cooking, we decided to melt them.
It's actually a braise, but the result is meltingly good. And braising requires only an occasional stir.
The leeks are thinly sliced, then slowly simmered in broth or stock until extremely tender, then the whole mixture is stirred into the potatoes.