Cook the pasta in salted water until al dente. In the meantime, chop the sage leaves into small pieces and gently sauté them in the butter. After about 5 minutes, add the crayfish to the butter and sage mixture in the pan. Season with salt and pepper and add garlic if necessary. Heat briefly and deglaze with the juice of the lime. Add the cooked and drained pasta to the pan and mix everything together.