The 24-year-old Argentinian arrived on Teesside this summer and has been a mainstay in Mowbray's promotion-chasing side of late, netting three times, with the latest strike a wonderful curling free-kick in Tuesday's 3-0 victory over Huddersfield.
Mowbray revealed he was impressed with Ledesma during his stint at Walsall last season and praised the patience he demonstrated in waiting for a chance to break into Boro's starting XI.
"The kid's got talent," said Mowbray.
"We watched him last year and yet he spent most of the first dozen or so games sitting on the bench learning how to play for us because he loves the game so much. He runs around everywhere and just wants to play like a kid in the school year.
"Obviously at a higher level he's playing at now you need to be a team player, you need to play your position and yet nobody has ever questioned his talent and his quality."