Caramelized-onion tart with asparagus



20 min


12 Servings

* PLUS Baking Time: 35 minutes
Caramelized-onion tart with asparagus

Caramelized-onion tart with asparagus.
Photo, Michael Graydon.

This decadent tart with asparagus, light cheese and caramelized onions will be sure to impress guests. Cut into bite-sized rectangles and serve.


  • 2 tbsp olive oil
  • 1 red onion , thinly sliced into rounds
  • 1 tsp granulated sugar
  • 1/2 tsp salt
  • 2 tsp balsamic vinegar
  • 1/2 397-g pkg frozen puff pastry , thawed
  • 1 egg
  • 1/2 bunch asparagus , about 250 g, trimmed and sliced in half lengthwise
  • 1/2 cup kalamata olives , pitted and sliced
  • 1 cup grated fontina or mozzarella


  • Heat a large non-stick frying pan over medium. Add 1 tbsp oil, then onion. Sprinkle with sugar and 1/8 tsp salt. Cook, stirring occasionally, until caramel coloured, about 12 min. Stir in vinegar.
  • Position oven rack in lower third of oven. Preheat to 400F. Line a baking sheet with parchment paper. Roll out pastry on a lightly floured surface into a 14×10-in. rectangle. Pastry will be thin, and edges will be uneven. Transfer to lined baking sheet. Beat egg with 1 tbsp water in a small bowl. Lightly brush pastry with egg wash. Set aside.
  • Drizzle asparagus with remaining oil and sprinkle with remaining salt. Season with fresh pepper. Toss to coat.
  • Scatter caramelized onion and olives over pastry. Sprinkle with 1/2 of cheese. Arrange asparagus spears in 2 parallel rows on cheese. Sprinkle with remaining cheese. Bake in lower third of oven until pastry has puff ed up and cheese is melted, 20 to 25 min. Cut into bite-sized rectangles and serve immediately.

Nutrition (per serving)

  • Calories
  • 186,
  • Protein
  • 5 g,
  • Carbohydrates
  • 12 g,
  • Fat
  • 13 g,
  • Fibre
  • 1 g,
  • Sodium
  • 307 mg.