Culinary adventurer Valentine Warner turns his attention this week to some of his favourite autumn vegetables – pumpkin, onion and beetroot.

Valentine believes beetroot is sadly misunderstood and, when cooked from fresh, it can be amazing. This honey-sweet crimson beauty makes amazing iron-rich salads and soups.

To find the very best variety for his beetroot with green sauce recipe, Valentine visits Spencer Christy, a biodynamic farmer in Essex who believes that the lunar cycles affect the growth of plants and follows an astronomical sowing and planting calendar.

One of Valentine’s lasting childhood memories is the taste of his dad’s perfect pumpkin soup. Armed with this very special recipe, he heads to Banbury, home of American farmer Greg Klaes who specialises in vegetable growing with a penchant for pumpkins. Using four different varieties, Valentine follows his father’s recipe inviting Greg and his family to put it to the test.

Valentine is not alone in his appreciation of the humble onion. In September the Gloucestershire town of Newent holds its annual Onion Fayre, where like-minded individuals come to celebrate this most versatile of vegetables. Valentine shows his competitive streak when he enters the raw onion-eating contest in an attempt to break the world record for eating a single onion in the fastest time. He also cooks up a deliciously sweet onion tart.