In a large sauce pan add butter then sauté garlic and onion, cook in low heat until onions are soft.
Add the flour and mix well, making sure all the butter is absorbed by the flour.
Gently pour the chicken stock while continuously mixing.
Add the cream, mashed white beans, parsley and red pepper flakes. Mix well and let it simmer for 5 minutes in low heat or until sauce thickens.
Season with salt and freshly ground black pepper.
Pour sauce on top of cooked pasta then stop with generous amounts of Parmigiano-Reggiano.
