How a bakery in Cornwall produces 180,000 Cornish pasties a day. There are rules: A Cornish pasty must be made in Cornwall; the filling can only contain onion, potato, swede, beef and some seasoning; and each ingredient must be cooked from raw within the pastry parcel. The versatility of onions, and how they make us cry. How anaerobic digestion turns food factory waste into electricity. Challenging the pasty's origin story. How importation of pepper eventually transformed it from a precious commodity to a spice that everyone could afford.

• Gregg Wallace
• Ruth Goodman
• Cherry Healey