In a large, deep skillet, heat the oil until shimmering. Add the garlic and crushed red pepper and cook over high heat for 30 seconds, until fragrant. Add the escarole, season with salt and pepper and cook, tossing, until wilted and just beginning to brown in spots, about 4 minutes. Add the tomato puree and 1 cup of the reserved pasta cooking liquid. Add the pasta and cook, tossing frequently, until coated with a thick sauce, about 1 minute. Add more of the pasta cooking water if necessary. Stir in the tuna and olives, season with salt and pepper and transfer to a large bowl. Serve right away.