Leave the butter at room temperature until it become soft, meanwhile cut the truffle in a thin slices.
Mix the butter with the truffle and adjust seasoning, leave the mixture on the fridge for at least 3 or 4 hours.
Wash the green beans and cut them in 1 cm pieces, then cook them in salted boiling water for 5 minutes. Put the green beans in a bowl with cold water in order to stop the cooking.
Cook the Tagliatelle Filotea for 4 minutes in the same water where you cooked the green beans, drain the egg pasta and toss it with the butter and truffle blend.
Add the green beans and some curls of truffle butter on top, then serve the dish immediately and enjoy!