He finds himself endlessly intrigued as to whether the food then was "any more Irish than what we eat now", and says he's fascinated with how 'terroir' cooking (using indigenous ingredients) now would compare.

You can see why the Galway-based restaurateur was tasked with compiling new recipe compendium, The Irish Cookbook. The weighty collection investigates the 'peasant tradition' presumption, explores historical and contemporary cooking (McMahon went deep into Irish recipe archives), and champions the produce Ireland naturally offers up.

And it turns out, 10,000 years ago, Ireland's first settlements were busy with people scoffing stuff you'd still recognise today. "The three pinnacle foods would've been: salmon, trout and eel," explains McMahon. "You also had a lot of wild game, duck - particularly mallard - pigeon and woodcock, and then a whole host of indigenous plants, such as wild garlic, nettles."

People would have also been cracking open oysters and scallops, mussels, cockles and clams, not to mention cooking up dishes of seal, puffin, squirrel and bear. The bears are of course all gone now though. "I don't think we ate them all...," McMahon notes wryly.

When people think about Irish food though - your lamb and barley, beef and Guinness stews - McMahon says "they're really thinking about it in the last 200 years. A lot of these recipes only date to the 19th century, and once you go back beyond that point, it gets very, very messy," he adds.

So messy in fact, you get exotic things like meringue popping up, and more regionally, things like birch wine made from tapping and fermenting the sap of birch trees, "which was a common thing to do".

It all makes writing a cookbook about 'Irish food' quite difficult - it's impossible to be definitive. For McMahon, "whatever was eaten in Ireland is part of Irish food" - but then that has to include the criss-cross of dishes between England and Ireland, the Chinese takeaways on every Irish high street, and his own restaurants, from the Michelin-starred Aniar, to casual tapas joint, Cava Bodega. "When we think about national cuisine, it doesn't really exist, it is a figment of our imagination."

Taste and flavour are very real though, even if some are taken for granted. Black pepper, spices, citrus - none are indigenous to Ireland, so McMahon will incorporate woodruff and meadowsweet, rather than cinnamon and allspice, when making a carrot cake of Irish terroir. He can't help but interrogate why people opted for far-flung spices, rather than what was readily available nearby.

Much can be put down to showing off - spices and sugar indicated wealth, while even the act of writing down recipes was acquired from elsewhere. Cookbooks, by women mainly, were introduced to Ireland via the English, when they began settling there in the 16th century, and "weren't part and parcel of the Irish canon, because post-independence we couldn't reconcile with our own history".

Some indigenous ingredients also just deserve more respect. McMahon would particularly like Ireland to be associated with "two very elemental foods" - seafood and seaweed. "They've been here a long, long time," he explains, but the tradition of seaweed is very small.

Ideally, we'd all be better acquainted with what we're eating and where it comes from. "It's so important to be able to talk about what you're buying," says McMahon, "even if you're buying vegetables. Just being able to ask someone, 'Is that in season? Where is it from? What variety is that?'

"We just think a carrot is a carrot, or a plum is a plum. And the interesting thing is, when you look at all the recipes, [historically] they understood there are different varieties of plums, and some of them are better for some things than others."

The ubiquitous orange carrot is basically acting as shield to all the other knobbly, gnarly, sunset-hued carrots we could be crunching through. "There's a massive world of vegetables out there."

"For a lot of people, food is just a vehicle for hunger and nutrition, and for me, food should be a cultural experience," he says. "How do we reclaim that?" The Irish Cookbook is a good start.


Brown soda bread with stout and treacle

Ingredients:

(Makes 2 loaves)

Rapeseed oil, for greasing

800g strong brown (wholewheat) bread flour

200g strong white bread flour

1tbsp bicarbonate of soda

20g sea salt

3 handfuls of mixed seeds (such as pumpkin seeds, sunflower seeds and linseeds/flaxseed)

200g treacle

2 eggs

850ml buttermilk

200ml stout

50g pinhead oats, for the topping

Method:

1. Preheat the oven to 130°C/265°F/ Gas Mark 3/4. Grease two 23 x 13 x 7-cm loaf pans.

2. Stir all the dry ingredients together in a large mixing bowl. Add the treacle, eggs and buttermilk and combine, then add enough stout until you achieve a wet dough.

3. Pour the dough into the two prepared loaf pans, sprinkle the oats on top and bake in the preheated oven for one hour 30 minutes to one hour 45 minutes, until the loaves sound hollow when the bottoms are tapped or the core temperature is greater than 85°C/185°F on a meat thermometer.


Seafood and seaweed chowder

Ingredients:

(Serves 4)

For the stock:

2tbsp rapeseed oil

1 onion, diced

1 carrot, diced

1 celery stalk, diced

250ml dry cider

25g dried kelp or kombu

3 cloves garlic, peeled

2 bay leaves

A few sprigs of thyme

500g mussels, scrubbed clean

500g clams, scrubbed clean

For the chowder:

25g butter

1 onion, finely chopped

600g potatoes, cubed

2 leeks, diced

250ml double cream

300G pollock fillet, skinned and boned, cut into small chunks

Sea salt

To garnish:

Chopped dill

Finely milled nori

Method:

1. To make the stock, heat the rapeseed oil in a large pan over a medium heat. Add the onion, carrot and celery and saute for about 10 minutes until they start to caramelize. Pour over the cider and cook for a couple of minutes. Pour in one litre of water and add the seaweed, garlic, bay leaves and thyme. Bring to the boil, then turn the heat down and simmer for 40 minutes.

2. To finish, cook the mussels and clams in the stock for three to five minutes until they open. Remove from the stock and place them in a suitable container, discarding any that haven't opened. When cool enough to handle, pick the meat from the shells and discard the shells. Strain the stock through a fine sieve.

3. For the chowder, melt half of the butter in a large saucepan over a medium heat. Add the onion and saute for three to four minutes until translucent. Add the potatoes and leeks and stir to mix. Add the seaweed stock. Season to taste. Bring to the boil, then turn down the heat and simmer for about 15 minutes until the vegetables are tender. Add the cream and warm through.

4. Add the pollock and cook for two minutes. Finally, add the mussel and clam meat and remove from the heat. Allow to stand for five minutes.

5. To serve, fold the chopped dill through the chowder and divide among four warmed bowls. Garnish with a sprinkle of milled nori.


Coddle

Ingredients:

(Serves 8)

2tbsp rapeseed oil, plus extra if needed

500g sausages, cut into pieces if preferred

500g streaky bacon, cut into pieces

500g onions, sliced

2tbsp chopped thyme

2 bay leaves

1 litre chicken stock

1kg potatoes, peeled and cut into chunks

4tbsp chopped parsley

Freshly ground black pepper

Method:

1. Warm the oil in a large pan over a medium heat. Add the sausages and bacon and fry for about 10 minutes until they have a nice colour. Remove the meat from the pan and set aside.

2. Add the sliced onions to the pan and a little more oil if necessary. Reduce the heat and fry for about 10 minutes so that the onions caramelize slowly.

3. When the onions have a nice colour, return the sausages and bacon to the pan and add the thyme and bay leaves. Cover with the chicken stock (broth) and return to the boil. Reduce the heat to a simmer and add the potatoes. Cook for about 30 minutes.

4. Add the chopped parsley and plenty of black pepper and serve.

The Irish Cookbook by Jp McMahon, photography and styling by Anita Murphy and Zania Koppe, is published by Phaidon.