The amber, auburn and crimson colours of autumn cosy up on top of one another, each layer dotted with patches of green, waving gently in the wind. This description is not one of the Lake District landscape before me, though it does match those views. Rather, it’s of the cabbage and butternut squash sabzi that’s just been handed to me by Harrison Ward on the summit of Black Fell – cooked on a camping stove with red onion, diced garlic and ginger, ½ teaspoon nutmeg, ½ teaspoon turmeric, accompanied by a freshly made flatbread and topped with coriander.

Better known to many as Fell Foodie, Harrison is an Ambleside local who has acquired a substantial Instagram following for cooking up extravagant meals on the fells. “I’ve always loved that mindful experience of crafting a meal and sharing food with people,” he says. “Food plays a huge part in my own life, so why go outdoors and leave that passion behind?”

Harrison has just released his debut book Cook Out, and the sabzi is one of 85 recipes included.

It’s not a common sight on a mountain summit: someone whipping out a chopping board and a hefty kitchen knife, cutting up cabbage, cubing squash, stirring in turmeric and cooking it all to a gentle simmer, but it certainly makes the meal more memorable than some dehydrated noodles.

“I get the convenience of dehydrated meals, but they’re actually quite expensive – and I’ve never really enjoyed that side of food,” says Harrison, chopping through a red onion. “It feels like we’ve lost that connection with our food, and to the conversations it can bring about.”

He laughs, adding: “I’m certainly now inundated with offers to join me on the hillside.”

I don’t doubt it. We’d set off a couple of hours earlier from our lakeside pitches at Low Wray campsite on Windermere, and hiked up a muddy trail weaving through the wobbly dry stone walls that dissect the countryside here, rising gradually up Black Fell.

Harrison’s backpack looked weighty enough, but it wasn’t cartoonishly large, as you’d perhaps expect for someone hauling half a kitchen up a fell top. “The challenge, the humour and, at times, the ridiculousness of it is not lost on me at all,” he says. “When you’re grating nutmeg on top of a fell or using a pestle and mortar to make your own curry paste, there’s a bit of that.

“Some might say it’s pointless but ultimately, I suppose, so is going up the hill in the first place.”

On the contrary, few people have found such meaning in both endeavours as Harrison, whose cooking and hiking is also intrinsically linked to his mental health. Harrison is seven years sober, and speaks regularly about his struggles with alcoholism and depression.

“I was quite extroverted and happy-go-lucky from a young age, but internally I was ripping myself apart,” he says. “I didn’t want to be a burden, so I didn’t share it. I felt very alone.”

After moving to York for university and getting a bar job, Harrison became dependent on alcohol. “I was battling with my own existence, and using alcohol to shut off those thoughts,” he says. “Alcohol became my sole focus. I was brushing my teeth with the stuff. Around my 21st birthday, I was consuming in excess of 20 pints a day and I had ballooned to 22 stone [140kg]. I continued that lifestyle for years – drinking to blackout, just to escape for a moment.”

It was the end of a relationship with a partner that led to the end of Harrison’s relationship with alcohol. “It was 6 June 2016,” he recalls. “That was my last drop. Overnight, I left York and moved on from that life – and the thing that I replaced alcohol with was fitness.”

Two weeks later, back in Cumbria, a friend bought Harrison an entry-level pair of hiking boots and took him up Blencathra – no easy first summit. The next week, it was Helvellyn, England’s third highest point. “The moment I hit the top, it was blue skies, glorious views, Striding Edge below, and something else sparked in me; a new addiction had been ignited,” he says.

Harrison climbed Scafell Pike the next week, then Snowdon, then Ben Nevis. About 11 months after going sober, he had shed 44kg and had run the Brathay marathon around Windermere.

Harrison didn’t cook steak frites on Ben Nevis right away. “But I was taking lunch out that I’d made at home – trying to eat healthily,” he says. “Then I got my first stove. I did a nice Cumberland sausage and mash in gravy, and a beef and ale stew. I started sharing them on Instagram with vistas, and it got people’s attention.” So much so that in 2021, he found himself making a cake for Mary Berry on her BBC show Love to Cook. “She said the immortal line – ‘no soggy bottom’,” Harrison smiles.

Now there’s an outdoor cookbook, and Harrison has climbed more than 190 of the 214 Wainwrights in the Lake District, one of which we’re sitting atop. “It still feels a bit surreal,” he says.

The 360-degree views from Black Fell bely the short walk to reach it. The expansive valley rises up to the rocky ridgeline of Bowfell and the Langdale Pikes, which backdrop Lingmoor Fell. The lakes of Tarn Hows and Coniston Water sit south-west, Esthwaite Water and Hawkshead are south-east and Windermere is to the east, with Wansfell Pike rising above the head of the lake.

The scent of turmeric wafts upwards as Harrison hands over the sabzi.

“There’s a degree of insignificance about being outdoors,” he suggests, as we eat. “It puts your problems into perspective – these vistas and open spaces. It feels like the reset we require.”

After lunch we pack up, and head back down the hill, hiking on to our next cook spot. We settle just above Slater Bridge, backdropped by the Langdale valley. Wainwright described it as “the most picturesque footbridge in Lakeland, a slender arch constructed of slate from the quarries”.

The pots, pans, gas canisters and stoves come back out for dinner – a chickpea, spinach and coconut curry. Courgettes are chopped, spices mixed and rice boiled. A heckle of “season finely!” comes from some passing teenagers giggling at the grandeur of our makeshift kitchen, and Harrison happily obliges. The curry is fantastically flavoursome.

We pack up carefully afterwards. “For me, the outdoors has been a hugely healing environment, so it’s about ensuring you leave it the same way for the next person,” says Ward.

Darkness falls as we head back to Low Wray campsite for the night. When I wake to the sight of the sun beating down on Windermere, and the honking of geese, it’s my turn to make breakfast.

With guidance from Cook Out, I’d pre-made some pancake mix and pour it into my pan. “Does that gas sound odd?” I wonder, the stove crackling. “I think it’s the butter burning,” says Harrison.

Still, I whip up a fine round of American-style pancakes, topped with blueberries and dripping in honey. I’ve chosen perhaps the simplest recipe in the book, but there’s an inherent satisfaction in the process – and it certainly beats a dry breakfast bar. “A nice backdrop, fresh air and good food,” says Harrison. “What’s better?” Admittedly, it’s a tough question to answer.

• Cook Out by Harrison Ward (Vertebrate Publishing Ltd, £25). To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.