the big enchilada

US /ðə bɪɡ ˌɛntʃɪˈlɑːdə/
UK /ðə bɪɡ ˌɛntʃɪˈlɑːdə/
"the big enchilada" picture
1.

the most important person or thing

:
He thinks he's the big enchilada around here, but he's not.
Getting this contract would be the big enchilada for our company.