The Modern Family beauty was joined by her husband, Joe Manganiello, and friends and family at the secret outdoor bash in Los Angeles, where guests enjoyed food from actor Danny Trejo's new vegan eatery, Trejo's Tacos and were treated to live music by a mariachi band.

She took to Instagram on Saturday (17Sep16) to share a collection of photos from the event, with one image showing the proud mum, who wore a red dress with cut out detailing and a low neckline, standing beside Manolo and his three-tier, tri-colour birthday cake, which had a little model of a mariachi musician perched on top.

"Happy bday Manolo!! Mexican Fiesta!!" she captioned the snap.

Another picture featured Sofia and a female relative donning mini sombreros and fake moustaches, while she also posted a shot of herself munching on a taco, and another of Magic Mike hunk Joe pretending to join in with the mariachi band.

Manolo is the star's only child from her first marriage to Joe Gonzalez.