Guilty pleasure? Chips with tomato sauce, which I have maybe three times a year.
Where is home? An Edwardian house in St Albans, where I recently moved, and Sydney, Australia, where my partner Michele lives. Home is where the heart is.
Career plan B? I would love to be a professional musician. I’m the drummer in a band called Little Moscow, but that’s just for fun.
Who would play you in a movie of your life? Jeff Bridges.
Biggest bugbear? Brexit – I’m definitely against.
As a child you wanted to be… A lighthouse keeper or a coastguard. I grew up near the coast and love the sea.
Earliest memory? Sitting on my grandfather’s knee, eating a boiled egg and soldiers.
Secret to a happy relationship? Compromise.
Your best quality? Generosity. And your worst? Lack of patience.
Most romantic thing you’ve ever done? Travel across the world to tell Michele I love her, which I do regularly.
Last meal on earth? A bacon sandwich and a cup of tea.
Dream dinner-party guests? Bob Dylan, Che Guevara, Jeff Bridges, Isabelle Adjani, Cary Grant, Gina Lollobrigida, [fellow Hairy Biker] Dave Myers, Michele and my three sons.
Advice to teenage self? Enjoy the ride and play more drums.
Cat or dog? I’ve got a labradoodle, Artie, and there are more cats in the family than I care to mention.
What do you see when you look in the mirror? Confusion.
On a day off we’d find you… At the beach. My favourites are Bamburgh in Northumberland and Merewether in New South Wales, Australia.
Starstruck moment? Meeting Pink Floyd’s drummer Nick Mason at a charity event about five years ago.
Big break? Roly Keating, the then BBC Two controller, commissioning the first Hairy Bikers series in 2004.
Career highlight? All the travel I’ve done with my best mate Dave. Looking up at the night sky by the Messum Crater in Namibia, listening to Pink Floyd’s ‘Wish You Were Here’ and seeing the Milky Way was incredible.
Favourite tipple? Pinot noir.
Hangover cure? More pinot noir!
What did you have for breakfast today? A fruit salad.
Top of your bucket list? To sail across the Atlantic and to ride a motorcycle from the tip of Alaska to Tierra del Fuego in Argentina.
One thing that would make your life better? Having Michele live closer.
Philosophy? Treat the world with a gentle heart.
Biggest lesson you have learnt about money? It’s hard to keep.
Biggest lesson you have learnt about women? You never stop learning.
Where would you time-travel to? Buenos Aires, Argentina, in the 1920s. There was a mix of big business, money, incredible architecture, great music and the tango was at its height. It would have been an amazing scene.
First record you bought? Live and Dangerous by Thin Lizzy.
Most extravagant purchase? A dreamscape painting by an Aboriginal artist.
Biggest fear? Loneliness.
Celebrity crush? Most of them!
Happiness is… Food, friends and familiarity.
Si and Dave’s new cookbook, The Hairy Dieters Make It Easy: Lose Weight and Keep it Off the Easy Way, is published by Seven Dials, price £16.99. To order a copy for £12.74 (A 25 per cent discount) until 1 July, visit mailshop.co.uk/books or call 0844 571 0640; P&P is free on orders over £15.
Interview by John Koski