Go Back

Caramelised Onion Tart

Prep Time35 minutes
Cook Time1 hour 20 minutes
Total Time1 hour 55 minutes
Course: Lunch/Dinner, Main Course
Keyword: seasonal,, vegetarian,
Servings: 6 people

Equipment

  • 25cm Tart tin

Ingredients

  • 1 kg brown onions peeled & sliced
  • 40 g butter
  • 1 tbls olive oil
  • 100 g crème fraîche
  • 90 ml milk
  • 1 egg
  • 1 egg yolk
  • 1.5 Tbls wholegrain mustard
  • 1 tbls chopped herbs ie. thyme or chives
  • 1 tbls grated mature cheese ie. cheddar or Parmesan

Pastry

  • 100 g wholemeal spelt flour
  • 80 g white spelt flour
  • 80 g cold butter diced
  • 60 g Greek-style yogurt full fat

Instructions

  • Preheat the oven to 180°C fan.
  • Begin with slicing the onions, use a mandoline if you have one. Heating the butter and oil in a pan and cook the onions and garlic for 45-60 mins, stirring occasionally on high at first, then reduce the heat and cover with a lid. Cook until they become sticky and golden. Remove from the heat and cool to room temperature.
  • To make the pastry, tip the flour and butter into a bowl, add a pinch of salt then rub together with your fingertips until completely mixed and crumbly. Add the Greek yogurt, then bring everything together with your hands until just combined. Roll into a ball and chill for 30 minutes.
  • Lightly grease the base of the tart tin. Roll out the pastry on a lightly floured surface to approximately 5cm larger than a 25cm tin. Use your rolling pin to lift it up, then drape over the tart case so there is an overhang of pastry on the sides. Using your fingers to push the pastry into the corners of the tin. With you fingertips pinch off the excess pastry. Chill in the fridge for 15-20 minutes.
  • Increase the oven temperature to 190°Cfan.
  • Lightly prick the base of the tart with a fork, line the tart case with a large circle of greaseproof paper or foil, then fill with baking beans. Blind-bake the tart for 10 mins, remove the paper and beans, then continue to cook for 10-12 minutes until biscuit brown.
  • Whisk the egg and egg yolk with the crème fraîche and milk. Add the wholegrain mustard and cooled onions. Season with salt and pepper. Pour into the pastry case and sprinkle with fresh herbs. Bake for 22-25 minutes or until golden and set. Serve warm sprinkled with grated cheese (optional) with a bitter leaf salad.