Cortar el bacalao

[ROBINDESBOIS]

EJEMPLO :
Alejandro es el que corta el bacalao en esa familia. Cortar el bacalao, la persona que corta el bacalao, es la persona que toma las decisiones o la que lleva la voz cantante. Se usa en todos contextos, trabajo, familia, amistad etc...
Cual sería el equivalente en inglés?

[ROBINDESBOIS]

Otra forma de decirlo es el que ordena y manda. In English?

[poli]

The decision maker.
The one who wears the pants.

[ROBINDESBOIS]

well, but to wear the pants, I thought it was for couples.

[poli]

Yes, with couples, but with households also.
You could also use : the one who calls the cards.
example: when it comes to decision making , she's the one who calls the cards/wears the pants.

[EmpanadaRica]

He/ She calls the shots/ He's or She's the one calling the shots.
(Though perhaps this is more used outside domestic contexts so you should add ' at home' in this case I think ;))

[Tomisimo]

Corta el bacalao.
He's the boss.
He calls the shots.
He's the decision maker.
He's the head honcho.
He's the big cheese.
He's runs the shop.
He's in charge.