Traditional Colcannon 4 slices bacon, finely chopped 1/4 cup finely chopped shallots, red scallions or onion 2 cloves garlic, minced One bunch black kale, tough stems removed, and finely chopped, or cabbage cut into 1/2-inch ribbons 6 medium Sierra Gold potatoes, scrubbed and peeled if desired, cut into 1-inch chunks 1/2 cup heavy cream 1/4 …