Benny Blanco says his fiancé Selena Gomez isn't too big on flowers ... so he got her the next best thing for Valentine's Day ... a bathtub filled with cheese!!!

The famous music producer just shared video of his romantic gift for his bride-to-be ... and he's filled a tub with melted queso and left a trail of tortilla chips leading to the prize.

Benny even took the chips and spelled out "I Love You" ... a move generally reserved for rose petals.

But as Selena's man explains, this is what must be done "when your fiancé isn't much of a flowers girl."

Benny shared video of the sweet salty gesture on Instagram and added some music for extra effect ... going with his new song with Selena, "Scared of Loving You."

Cheese and tortillas are actually a big part of Benny and Selena's love story ... when he popped the question last year, his proposal included a Taco Bell picnic.

Looks appetizing, at least for Benny ... he's already stuffing his face.