prendere due piccioni con una fava significa in inglese

kill two birds with one stone▼(solve two problems at once)
verb
[UK: kɪl ˈtuː bɜːdz wɪð wʌn stəʊn] [US: ˈkɪl ˈtuː ˈbɝːdz wɪθ wʌn ˈstoʊn]