1 pound kale, (approximately 2 medium heads)
3 tablespoons extra-virgin olive oil
6 garlic cloves, peeled
½ cup pancetta or bacon, cut into 1/4 x 1/4 x 1-inch strips
¼ teaspoon crushed red pepper, or to taste
Remove the outer leaves of kale if damaged or discolored. Cut off the bases of the stems, wash the leaves twice in abundant cold water, and drain. Cut the leaves crosswise into 1-inch strips.
Heat the olive oil in a wide, heavy skillet over medium heat. Whack the garlic cloves with the side of a knife and toss them into the oil. Stir in the bacon and cook, stirring, until the bacon and garlic is light golden, about 4 minutes.
Stir as many of the kale leaves into the skillet as will fit comfortably. Cook, stirring, until wilted enough to make room for more kale. Continue adding the kale, a handful at a time, until all the kale is in the skillet. Season lightly with salt and 1/4 teaspoon crushed red pepper. Cover the skillet, lower the heat to low, and cook, stirring occasionally, until tender, about 10 minutes. If all the liquid in the pan evaporates and the greens begin to stick to the pan, sprinkle a tablespoon or two of water over them. Taste the greens and season with additional salt and red pepper if you like. Serve immediately.