-Wash 1 bunch of collards.

-Working in batches, stack greens; cut crosswise into 2-inch-thick strips. Gather strips; cut crosswise into 2-inch pieces.

-Transfer to a large bowl of cold water; swish to remove grit.

-Transfer greens to a colander using a slotted spoon; let drain. Repeat until greens are free of grit.

-Heat 2 tsp extra virgin olive oil in a very large skillet over medium-high heat.

-Cut 1 leek in half the long way, then clean between the layers.

-Chop the leek into thin, half-moon sized pieces.

-Cut 4 strips of thick cut bacon into ¼ inch strips.

-Add leek and bacon; cook until onions are translucent, about 4 minutes.

-Add greens; cook, stirring, until greens begin to wilt and are reduced in volume.

-Raise heat to high; add 2 TBS cider vinegar.

-Cook, scraping up brown bits from bottom of skillet, until vinegar has evaporated, about 1 minute.

-Add 1 cup chicken or vegetable stock; reduce heat.

-Simmer, covered, until greens are just tender, 12 to 14 minutes, taste for salt.