Ingredients:

  • 1 sheet (250g) all-butter puff pastry, chilled
  • 1 small (700g) butternut squash, peeled and cubed into 1/2-inch pieces
  • 2 large (400g) yellow onions, thinly sliced
  • 2 tbsp (30ml) extra virgin olive oil
  • 1 tbsp (14g) unsalted butter
  • 1 tbsp (15ml) balsamic vinegar
  • 1 tsp (4g) brown sugar
  • 1 cup (100g) Gruyère cheese, freshly shredded
  • 2 tbsp (4g) fresh sage leaves, chiffonade
  • 1 tsp (6g) kosher salt
  • 1/2 tsp (1g) freshly cracked black pepper
  • 1 large egg, beaten

Instructions:

  1. Preheat oven to 400°F (200°C). Toss the 700g of cubed butternut squash with 2 tbsp (30ml) of olive oil, 1/2 tsp of salt, and 1/4 tsp of pepper on a baking sheet.
  2. Bake for 20 minutes until the edges are golden and the centers are tender.
  3. While the squash roasts, melt 1 tbsp (14g) of butter in your skillet over medium low heat. Add the 400g of sliced onions and the 1 tsp (4g) of brown sugar.
  4. Cook for 15 minutes until they are soft and caramel colored. Stir in the 15ml of balsamic vinegar at the very end to deglaze the pan and scrape up all those delicious brown bits.
  5. Roll out your 250g sheet of puff pastry onto a piece of parchment paper. Use a sharp knife to lightly score a 1 inch border around the edge, being careful not to cut all the way through. Prick the center area with a fork multiple times to prevent it from rising too much in the middle during the bake.
  6. Spread the caramelized onion mixture evenly over the center of the pastry, staying inside the border. Top the onions with the 100g of shredded Gruyère, then arrange the 700g of roasted squash on top of the cheese. Note: Layering the cheese under the squash helps glue the vegetables to the pastry.
  7. Brush the 1 inch border with your beaten egg wash for a glossy finish. Sprinkle the 2 tbsp (4g) of fresh sage chiffonade over the top of the tart. Bake for 20 minutes until the pastry is puffed and deep golden brown.