MATT Sinclair has come a long way since finishing runner-up on MasterChef two years ago.

Now the co-owner of acclaimed Sunshine Beach restaurant Sum Yung Guys, he returned to the reality cooking show tonight as a fully-fledged guest chef.

Cooking against contestant Khanh Ong, who hoped to be fast-tracked to the finals, Sinclair was just too good in the kitchen.

"I had a fair idea of what I wanted to cook as soon as I saw the pantry," he said.

"I remember when I took everything back to my bench and I laid everything out, I talked Shannon (Bennett) through what I was doing. As he was walking away I heard him say 'Jeez this kid's come a long way'. That felt good."

His smoked Thai sausage with charred squid and sour orange curry sauce earned a perfect 30 out of 30 from the judges. It's a score he could have only dreamed of earning when he was a contestant.

"When I finished plating it I was looking at it going 'That looks really good'. It looked really sharp," he said.

"I don't think I had that sort of clarity when I was in there as a contestant."

Viewers will next see Sinclair in season two of The Cook's Pantry, which he's currently filming in Melbourne.