In a small bowl, thin the XO sauce with 1 tablespoon olive oil. Add the remaining 3 tablespoons olive oil to a large, heavy-bottomed pan over medium heat. When shimmering, add the broccoli rabe and reduce to low.
Cook the rabe, covered, mixing occasionally, until the cooked but al dente, about 8 minutes. Remove the cover and add the thinned XO sauce. Stir to coat the broccoli and cook for an additional minute, then serve warm.