Mustardy baked onions

Mustardy baked onions

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(1 ratings)

Prep: 8 mins Cook: 45 mins


Serves 4
Simple oven-roasted red onions with punchy mustard and balsamic coating make a vibrant side that's really versatile

Nutrition and extra info

  • Vegetarian

Nutrition: per serving

  • kcal105
  • fat3g
  • saturates1g
  • carbs17g
  • sugars14g
  • fibre2g
  • protein2g
  • salt0.3g
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  • 4 medium red onions
  • 4 small sprigs rosemary



    Rosemary's intense, fragrant aroma has traditionally been paired with lamb, chicken and game…

  • knob of butter



    Butter is a dairy product made from separating whole milk or cream into fat and…

  • 1 tbsp balsamic vinegar
    Balsamic vinegar

    Balsamic vinegar

    bal-sam-ick vin-ee-gah

    True Balsamic vinegar is an artisan product from Modena, in Emilia Romagna, Italy, and is made…

  • 2 tbsp grainy mustard



    A condiment made by mixing the ground seeds of the mustard plant with a combination of…

  • 1 tbsp soft brown sugar


  1. Heat oven to 180C/160C fan/gas 4. Slice the root off each onion to create a flat bottom, then carefully peel, leaving the onion whole. Cut a deep cross in the top of each, then poke in a sprig of rosemary, dot with butter and place in a roasting tray. Pour a little of the balsamic vinegar over each one and season. Wrap the tray in foil and bake in the oven for 30 mins. Meanwhile, mix together the mustard and sugar and set aside.

  2. Remove the tray from the oven, take off the foil and spoon a little of the mustard mixture onto each onion. Return to the oven for 15 mins, uncovered, to caramelise.

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Comments, questions and tips

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14th Jul, 2012
These were truly delicious. So simple and really tasty. They smelled fantastic too and filled the house with yummy aromas. Will definitely make again.
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