Preheat oven to 425°F and line a large baking sheet with parchment paper or a silicone baking liner.
Roll out pastry to a 10×15 inch rectangle. Fold in edges of pastry ½ inch to form a border and crimp edges if you like. and pierce all over the inner part of the puff pastry with a fork. Brush all over inner portion and outside edge of puff pastry with egg wash.
Place sliced pears in a single layer onto pastry. Evenly spread caramelized onions over and between pears. Sprinkle with walnuts, followed by blue cheese.
Bake in preheated oven for 25 min. Drizzle with honey and serve warm.
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Notes
Caramelized Onions: You can buy store-bought caramelized onions, but they're simple to make yourself and they keep well for days in the fridge! For an easy method to caramelize onions, check out this Simply Recipes post!