HERE'S what's on tonight...

Mortimer and Whitehouse: Gone Fishing (BBC Two, 10pm)

In October 2015, just before he was about to embark on the Reeves and Mortimer 25th-anniversary tour, Bob Mortimer underwent a potentially life-saving triple heart bypass.

A few years before that, Paul Whitehouse also stared death in the face and had stents inserted in his arteries to help his blood flow.

While most people with heart problems of this magnitude take them as a sign to slow down, the two comedy legends seem determined to live their lives to the full.

"I don't want to make a big deal out of the heart stents," Paul explains. "When the guy did it he said, 'I didn't put them in just so you can sit by the fireplace', know what I mean?"

Over the past couple of years, the duo have returned to some of their best-loved characters - Bob's been on tour with long-time comedy partner Vic Reeves, while Paul has teamed up again with his old mucker, Harry Enfield.

However, for this new series, the duo have rekindled their own friendship, which stretches back for decades, over an unlikely pastime - fishing.

Paul, who is an experienced angler suggested to complete novice Bob that he take up the hobby to help recover from his heart operation.

And now, the two much-loved comedians are touring the country to fish in some of the UK's most picturesque locations.

Paul will be in charge of the fishing, while Bob is sorting the accommodation and cooking heart-healthy food.

From recipes, regrets, relationships and rituals; to childhood, comedy and the countryside, the pair will discuss all manner of topics, alongside the ever-present shadows of showbiz and mortality.

Bob says: "Paul is a lifelong friend and the chance to have one last adventure together before we snuff it was irresistible.

"He is an experienced angler and I haven't fished since I was a teenager. As a teacher, I expect him to be brutal."

"Paul is actually my current outdoors hero," he added on the Countryfile website.

"I had no idea he had such a deep knowledge of the countryside and the animals and plants in it. When he was a boy, he'd forged a real bond with his dad down the riverbanks in Wales and the Home Counties.

"You can't really be in love with fishing without understanding everything around it. "I've learnt so much from Paul and he's been very patient teaching me about the fragile ecosystem."

Paul is also excited about working with his old comedy pal.

"Before Bob Mortimer and I die of heart disease, we're going fishing all around the country," he says.

"I sold it to him by saying fishing is long periods of boredom punctuated by short, sharp periods of incredibly intense boredom. As a Middlesbrough fan, he lapped it up.

"We talk about life, love, the universe and the perilous state of our hearts.

"We're old mates, me and Bob, and we reckoned we could make something funny, poignant and entertaining out of that... what a heady mix. We are ourselves reflecting on life, comedy, the universe and big fish."

The insight into the hearts (literally) of two of the UK's best loved comics begins with a trip to Norfolk, where the duo try to catch one of Bob's favourite fish, the tench.

"If I were a British animal, I'd have to be the tench," he says.

"It's a fish that lives a lovely, lazy life at the bottom of the lake, seemingly sleeping a lot and taking the odd gulp of food that may pass by.

"It's very hard to catch though."

Mad About Elvis (BBC1, 7.30pm)

It's more than four decades since he died, but the spirit of Elvis Presley is alive, well and partying hard in Porthcawl, South Wales. This film examines the region's annual Elvis Festival, when thousands of fans descend on the Welsh seaside town for a unique celebration of The King. Among the devotees that pack the promenade, pubs and seafront Pavilion, are Festival Opener Darren Graceland Jones, a full-time Elvis tribute artist, whose bread and butter is performing as Elvis to dementia sufferers in care homes. It's narrated by Ruth Jones.

Great Rail Restorations with Peter Snow (C4, 8pm)

A rusting and tired Pullman dining car from the 1960s is the latest restoration project. Both the dining car and the wreck of a kitchen are in need of some serious renovation by the dedicated team at Tyseley Engineering Works in Birmingham, with heavy engineering to do, as well as meticulous attention to detail needed. Meanwhile, Peter's third driving lesson sees him grappling with reading signals, while still keeping the fire burning and the steam at the correct pressure, and Henry Cole delves into the history of catering on the railways.

Secrets of McDonalds: 50 Years of the Big Mac (C5, 9pm)

If you've seen rather good Michael Keaton movie The Founder, then chances are you already know a dramatised version of the Ray Kroc story. Okay, he may not be a household name, but this middle-aged milkshake machine salesman transformed Dick and Mac McDonald's burger restaurant into the world's most successful fast food chain. In this documentary, contributors tell the company's dramatic story, from 1948 to present day. Naturally once it conquered America, the franchise crossed the Pond, making its first appearance in Britain in 1974. Of course there has been no share of controversy over the years, and this film also analyses the backlash McDonald's weathered in the 1990s before attempting to project a healthier image.