In a large pot, heat the oil until shimmering. Add the ginger, garlic and crushed red pepper and cook over high heat, stirring until fragrant, about 30 seconds. Add the collard greens in 2 batches, wilting the first before adding more. Season with salt and cook over high heat, stirring occasionally, until the greens are just tender and the liquid is nearly evaporated, about 10 minutes. Stir in the sesame seeds, transfer the greens to a bowl and serve right away.