2 pounds tender greens, such as spinach, watercress or dandelion
greens—thick stems discarded, leaves coarsely chopped
2 large garlic cloves, minced
Pinch of crushed red pepper
Heat a large pot. Add the greens and cook over high heat, tossing just until wilted. Transfer the greens to a colander and press out the excess liquid.
Wipe out the pot. Add the olive oil and heat until shimmering. Add the pancetta and cook over moderately high heat, turning once until crisp, about 6 minutes. Using a slotted spoon, transfer the pancetta to a plate.
Add the garlic and crushed red pepper to the pot and cook over high heat, stirring, until fragrant and lightly browned, about 30 seconds. Add the greens, season with salt and cook over high heat for 2 minutes, stirring occasionally. Transfer the greens to a bowl. Crumble the pancetta on top and serve.
The greens can be refrigerated overnight. Reheat the pancetta and add to the greens just before serving.