With all the rules about what we cannot take in perhaps we should just stop buying EU products. Other countries will be along shortly with similar products. We will of course have to stop buying Fiat and Mercedes based MHs
They do check ...My son had some foodstuff in his hand luggage when flying from Thailand and stopped in France, it was removed. I suppose there aren't many places where one would come direct into the EU by ferry or train. On a plane you would have to eat the sandwich etc before disembarking. Had to do that when going to Australia as far as I remember. The mad thing is with UK that a lot of the produce came from EU in the first place. It's just that we now come under "third country" rules.
It’s very important to avoid importing foodstuffs between countries to prevent what can be devastating infestations. I’ve seen huge areas of forest devastated by an imported fungus in Tennessee. At US airports they have sniffer dogs checking that arriving passengers are not carrying food. Because the UK can now import food from wherever it chooses it is inevitable that the EU will seek to protect itself.