Ingredients

  • 3 medium onions
  • 1 tblsp olive oil
  • 100 g butter
  • wholegrain mustard
  • black onion seeds
  • salt and pepper

Method

  • Finely chop the onion and place in a saucepan along with the oil, butter, salt and pepper and onion seeds.
  • Cook with a lid on, gently simmering until they are completely softened but no colour.
  • Add the mustard and mix well.
  • Season and then pour into kilner jar and refrigerate.