I am sometimes asked, in interviews and by people who come on our River Cottage courses, who my culinary heroes are. I tend to say something along the lines of: Elizabeth David, for instilling in me the notion that the best food is intrinsically rooted in the soil and landscape of the region from which it comes; and Keith Floyd, for demonstrating that all good food has a people-based story, both in the production, and in the eating, and the best food television is simply the kind that tells a story with relish, good humour and respect. (OK, I know that's a bit stodgy. Let's hope it comes across a bit more chatty in a live session.)

But we all have other kinds of hero we don't very often mention, the kind whose names will mean nothing to the general population, and who have no opus to which other potential disciples can be directed. Often these are the people who have made the biggest differences to our lives.

One such hero in my life is a man called Dennis Cheeseman. He died recently, and he is particularly on my mind today, as I'm going to his memorial service tomorrow. Dennis was a schoolteacher and before that he flew in the RAF. But he was also a lobster and prawn fisherman, and this is the context in which I knew him, and remember him with great fondness.

Dennis lived in Osmington Mills, near Weymouth, and very near the holiday cottage which the parents of my best childhood friend, Charlie, rented for their summer holidays. Most years, from the age of about six to 16, I was invited to stay with the family, and we spent the best part of every day messing about on the beach at Ringstead Bay. Dennis kept his boat on the same beach. It was a beautiful wooden skiff, with a little outboard motor, perfect for his part-time second occupation of working a few pots to catch crustacea to sell to local pubs and restaurants. And every time he came in from hauling his pots we'd crowd round to see what he'd caught.

Being a schoolteacher, Dennis was on holiday in the summer, too. You'd have thought he'd had enough of kids, and that his potting was the perfect way to get away from them for a few weeks. But amazingly he responded to our goggle-eyed curiosity and prodding fingers by inviting us to come out with him on his boat, and help him pull his pots and sort his catch. To me the experience was sheer bliss. Every pot hauled was a lucky dip of wriggling and kicking marine fauna.

Spider crabs were something I'd never seen, and looked suitably prehistoric to be credible sea monsters. But it was lobsters he was really after, and when he caught one we'd all cheer. Getting the tail-thrashing, claw-waving critters out of the pots with your bare hands was a dangerous mission for a seven year old. Dennis wouldn't let us try at first – no doubt he didn't relish the prospect of dropping us back on the beach with a digit or two less than we'd set out with. But by the time we'd been out with him a few times, and he'd shown us how to handle the creatures properly, we were trusted. It felt like promotion, and we began to think of ourselves less as passengers, and more as crew.

But the prawn pots were always my favourites. Dennis would shake the contents out of them into a bucket, and when all the pots were hauled, he'd hand the bucket to us for sorting. We had to pick out the winkles, rockfish and tiny crabs. Our favourite thing to find was an astonishingly wriggly fish called a blenny. We were used to catching these in our nets in the rock pools on shore. But the ones in Dennis's pots were four or five times as big. We called them 'Cheesey size' in his honour, and they could give you a nasty nip – the kind that would make you scream but laugh at the same time. We'd put them in each other's boots or down our necks until Dennis would quietly tell us to pack it in, and make us chuck the poor thing overboard. He didn't mind fun and games, but he didn't like us being cruel for our own amusement.

And this was one of the great things about Dennis. He never made a big fuss about anything – but he didn't have to. He was the sort of person you naturally wanted to please, and he could always steer you in the right direction without ever raising his voice. Now that I have children of my own, I appreciate what a rare and delicate skill this is. It's the art of making those who look up to you feel good about themselves, and Dennis did it beautifully. It must have made him a great teacher.

I remember all this so well, because Charlie and I did this not once or twice, but many, many times. I don't quite recall how it came about, but what began as an occasional outing became a daily routine of the holiday. And not just for one summer, but year after year. For most of the children on the holiday, and there were often upwards of half a dozen in the cottage, going out with Dennis was an absolute high point. In the end a rota had to be drawn up to avoid fights about whose turn it was.

At least once every holiday, Dennis, his wife Pauline and daughter Caroline would invite all of us from the cottage, adults and children, for a picnic on the beach outside his boat hut. He would cook us a batch of his prawns, boiling them in fresh water from a nearby stream. After draining them, he would put them back in the pan, add a handful of salt, and give them a shake. I've read many times since that the best way to cook live prawns is to boil them in heavily salted water or, better still, seawater. But Dennis's prawns were as sweet as anything. The salt got onto the prawns mainly from your fingers, as you peeled them and, as a way of eating freshly gathered prawns, it takes some beating.

I don't know much about the rest of Dennis's kitchen repertoire. But I do know that for my love of boats, of fishing, of the sea and its delicious harvest, and for the fact that I chose to make my life in West Dorset, I owe him a huge debt of gratitude.

When I made the first series of River Cottage, I asked Dennis if he would take me out to haul his prawn pots again, and if we could film it for the programme. Very sportingly, he agreed, and afterwards we had a prawn picnic by the boat hut one more time. It was only then, as I relived that childhood thrill in a more self-conscious, adult mode, that I realised I had learnt as much from Dennis, about the importance of place, and people, in the pleasure of good food, as I ever did from Elizabeth David or Keith Floyd.

He is very much missed, and will leave a Cheesey-size hole in the lives of all who knew him.