The former West Bromwich Albion striker has signed a season-long deal with Boro and is looking forward to again linking up with former Baggies boss tony Mowbray.
"I'm very happy and excited to be reunited with Tony Mowbray and Mark Venus (assistant boss)," he said.
"Tony gave me my first shot of playing regular first-team football and I will always be grateful to him for that. Playing for Tony was the best time of my career so far.
"I'm just relishing the opportunity to play for Boro. I was excited when I heard Tony Mowbray was interested in me.
"I had a few different options but Tony knows what I can do and I really enjoy working with him."