In America, an onion pletzel is like an onion-topped focaccia, but to me – and more generally in the UK – it is a soft, chewy roll, a little larger and flatter than a bagel, with a dimple filled with fried onions and poppy seeds. Pletzels have to be eaten the day they are made – try a fresh one, warm from the oven, and you will wonder how you have survived so long without one.