Heat the oil in a 12-inch skillet over medium-high heat.
Add the ground lamb and brown slowly, scraping the bottom of the pan and reducing the heat as necessary to keep the lamb from browning too fast, until the moisture evaporates and the meat is well browned, 15 to 20 minutes.
Add a pinch of salt and the red pepper flakes and cook for 1 minute more. Drain off the fat.
Turn the heat to high, add the thyme, bay leaves, and wine, and stir well. Bring to a boil and reduce until only a small amount of liquid is left in the pan, 5 to 10 minutes.
Add the tomatoes and simmer for 20 minutes, or until the sauce thickens. When the sauce has thickened, remove and discard the thyme sprigs, bay leaves, and cheese rind, if you used it. Stir in the butter, cream, and grated cheese, bring to a simmer, and remove from the heat. Season to taste with salt and pepper. Add the fettuccine to the boiling water, stir to separate the strands, and cook for 2 to 3 minutes, until al dente.