Among his suppliers is the Matich family, which has been catching flounder and mullet from the Kaipara Harbour for at least three generations.
Leggott said all four Jones brothers from Onerahi each had a boat and supplied their catches to Fish to Fish.
There were many similar examples among his suppliers.
"It's all about fish and fishing for the people,'' Leggott said.
Dagny and Brad originally hail from Durban in South Africa and settled in the North after finding similarities in the lifestyle and coastal communities.
With his commercial fishing background, Leggott bought Stumpy's Takeaways on Riverside Drive, Whangārei
They grew the business over about 18 years and once they started processing scallops, they realised they had outgrown the site.
"We needed to spread our wings," he said.
About three years ago, they found the rundown processing premises in Herekino St, which had been used for crayfish and oyster processing in the 1980s.
"We had to reinstate everything and do a total revamp, but we have a lot more room now.
The site goes right through to the river. We have two chillers and rooms for blast freezing and a holding freezer.
"We also have separate areas for fish and scallop processing."
Leggott said a large part of the fishing industry in New Zealand revolves around building relationships.
"Since the Quota Management System was introduced in the 1980s, many families have owned their quotas and some can no longer fish themselves. We lease their quota and make sure we fulfil their financial needs.
"Maintaining good relationships is something I've worked hard at over the years.''
Leggott said ethical fishing is vital for Northland's fisheries.
Northland commercial fishermen can now sell their catch locally, and the fish are all processed in Whangarei when previously they would have been transported to Auckland, processed and resold back to Northland.
"We are not into big volumes. We're into sustainability and looking after the people of Northland.''
Leggott now supplies about 50 restaurants throughout Northland. Fish to Fish also operates a wet market at their premises every Saturday between 7am and 1pm.
"It's really popular. People love coming here to pick up their fresh fish from the source. There is nowhere quite like this in Northland."
While snapper is hugely popular, Leggott encourages people to try different species.
"I'm trying to educate people to eat different species, especially if they are concerned about the sustainability of the snapper fishery. If you are worried, try eating something else.
"There are so many other fish that are also great eating, including different species of dory, gemfish and southern kingfish.
"Try looking up different recipes and try making sashimi and raw fish. Get a bit more adventurous."
He also works closely with restaurants to try different cuts and different species.
Snapper wings are one example of how to use all parts of a fish.
"When we are processing, it's all about recovery. We don't want any meat being left on the frame.''
Nothing is wasted. They will often advertise on social media if there are bins of snapper heads available. Farmers use any remains for fertiliser.
Leggott said one of the advantages of Northland is the close proximity of both coasts.
"If the weather is bad on one coast we can often fish on the other. However, people have to understand that sometimes conditions are so bad our fishermen can't get out to catch any fish at all.''
For these times, some of the catch is frozen but the emphasis is always on fresh fish, "the fresher the better".