"We were already making doughnuts and with a similar dough we could bang out some brioche buns as well."
Gudsell bakes them fresh each day and has developed a range of filling options including fried organic chicken, braised beef cheek and marinated tofu burgers, along with a breakfast bun and doughnuts.
"I wanted a really nice soft fresh bun and really good fried chicken," he said.
"What I learned through my cooking overseas is to use the best ingredients you can get your hands on. Hence the organic chicken and local and quality ingredients."
Slim's buns are baked on site.
Gudsell said Slim's first two weeks had gone well.
"People seem to be into it and coming back for more, so that's a good thing."
Gudsell said it had been great working alongside the Common Ground Pop Up next door on the grassy area which has been kitted out by the Town Centre Regeneration Project.
"We complement each other because I don't do drinks and they don't really do food. They're awesome to work beside."
Gudsell will run the Slim's cart until April and assess its future then.
• Slim's is open Monday to Friday, 8.30am to 3pm. Doughnuts are also sold at the river market on Saturday.