11. May 2017
Onion and Tomato Relish

We prepared a delicious onion and tomato relish with none of the 14 main allergens. It is easy to make and can be used on meat, burgers, grilled vegetables, cheese, cream cheese, or as a spread.

For this recipe you need eyes that won’t cry while cutting onions and a bit of time. The reward is a sweet and sour delicacy that will take whatever you’re eating to the next level, whether it’s a barbecue dinner in the garden, a picnic in the park or a bread and cheese sandwich in your kitchen. If you can’t tolerate thyme, leave it out or replace it with rosemary. And if you like it sweeter rather than sour, just add a bit of sugar.

Ingredients for 1 medium jar

(makes around 200 – 250 ml)

  • 350g red onions
  • 150g tomatoes
  • 1 garlic clove
  • 2 Tbsp vegetable oil (e.g. olive oil)
  • 50ml dark balsamic vinegar
  • 2 Tbsp brown sugar
  • 2 – 3 fresh sprigs of thyme
  • Freshly ground pepper
  • Salt


  1. Peel and halve the onions. Slice them thinly or dice them. Peel and finely mince the garlic cloves.
  2. Heat the vegetable oil in a pot and add the onions and the garlic. Season with salt, freshly ground pepper and a few sprigs of thyme. Allow to caramelise on medium heat for around 30 minutes. Don’t forget to stir them once in a while to keep them from burning.
  3. In the meantime, cut a cross into the bottom of the tomatoes (opposite the stem) and cover them with boiling water. Let stand for 10 minutes. Remove the tomatoes from the water, peel and chop them finely. Or you can peel the tomatoes with a tomato peeler.
  4. After the onions have cooked for around 30 minutes, add the tomatoes, balsamic vinegar and sugar. Stir and allow to simmer on medium heat until the liquid has cooked off. This will take another 30 minutes or so. The longer you simmer the relish, the more flavourful it will become.
  5. Season again with salt and pepper to taste and, if you like, a bit more sugar. The thyme sprigs can be removed before serving if necessary.
  6. Pour the relish into a sterilised canning jar and seal it.
  7. Consume within three weeks.