Home - Recipes - Caramelized Onion and Mushroom Puff Pastry Squares

Caramelized Onion and Mushroom Puff Pastry Squares

Sweet onions are hit with a dash of sherry vinegar for a sweet-and-sour topping that perfectly complements the flaky golden pastry underneath.

Serves 25
Ready in 72 mins
Prep time 7 mins
Cooking time 65 mins
73 calories per serving


> 1 large yellow onion
> 3 tbsp olive oil
> 1/2 tsp dried thyme
> 1 (8 oz) pkg sliced white mushrooms
> 1 tbsp sherry vinegar
> 1/2 (17.3 oz) box frozen puff pastry sheets, thawed
> 1 tbsp finely chopped parsley


Preheat oven to 400°F. Finely chop the onion. In a 12-inch skillet, heat the oil on medium. Add onion and thyme. Cover and cook 20 min., until golden, stirring occasionally. Turn oven to 425°, uncover, and cook another 5 min.
While onion cooks, chop the mushrooms. Line a large baking sheet with parchment.
Add mushrooms to skillet. Cook 10 min., stirring occasionally. Stir in the vinegar. Season with salt and pepper to taste. Remove from heat and cool 10 min.
Unfold the puff pastry sheet on the lined baking sheet. Roll pastry out as thinly as possible. Spread mushroom mixture over pastry in an even layer.
Bake 25–30 min., until pastry is golden brown, rotating the pan halfway through cooking time. With a pizza cutter, slice into 5 columns and 5 rows to form 25 bite-size pieces. Garnish with chopped parsley.


The onion and mushroom mixture can be prepared up to 48 hours in advance and refrigerated. To reheat, microwave 1 min. until no longer cold before spreading on pastry.

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