

Why is the shelf life for a vegetable stir-fry mix so short? What's the secret to making perfect layers in a rocket ice lolly? And in Portugal, Kate investigates piri-piri.

Briony May Williams finds out why some radishes are hot. Andi Oliver asks why pre-made sandwiches contain mayonnaise. And Kate Quilton discovers how truffles are grown.

Matt Tebbutt is in Spain learning why some oranges are so hard to peel, while Jimmy Doherty heads to Thailand to discover why coriander is the herb of choice for some, but for others it seems to taste like soap. Briony Williams finds herself in a bit of a jam as she interrogates an important kitchen conundrum - why dropped toast always lands the wrong side down