EU referendum, brexit and the aftermath

A good practical example is food. We grow 61% of the food we eat, but if you look specifically at fruit and veg, there's a huge deficit in fruit and vegetable production. In 2015, imports of fruits to the UK were valued at £3.1 billion; imports of fresh vegetables (excluding potatoes because they're not vegetables they're a carb) at £2.1 billion.

55% of our tomatoes come from the EU - a lot from the Netherlands, which despite being tiny is the second largest exporter of food behind only the U.S. (because they've embraced modern high tech farming methods).

How do we come about those figures? I hope its not from Supermarkets saying "we sold x amount of ORIGIN - UK labeled stock"
Because you'd never suspect the UK producers to paper over an unforseen supply shortage due to weather with some euro stock to fill in the gaps...