A modern twist on the holiday classic, this Green Bean Casserole Tart uses golden puff pastry as the base for a rich, creamy topping of mushrooms, green beans, and crispy onions. It’s the kind of dish that works as a show-stopping side, an elegant appetizer, or even a light lunch. All the nostalgic flavours, but elevated and flaky.

—

Table of Contents

• Ingredients
  
• How to make a puff pastry tart with green bean casserole
  
• Tips for success
  
• FAQ
  

—

Ingredients

For the tart:

• 1 sheet frozen puff pastry, thawed overnight in the fridge
  
• 2 tablespoons butter
  
• 1 shallot, minced
  
• 175g cremini mushrooms, sliced
  
• 2 teaspoons finely chopped fresh rosemary
  
• ¼ cup white wine
  
• 1 tablespoon Dijon mustard
  
• 1½ cups frozen cut green beans
  
• ½ cup 35% cream
  
• ¼ cup grated parmesan cheese
  
• 1 tablespoon chopped fresh chives
  
• Pinch of freshly ground nutmeg
  
• Pinch of cayenne pepper
  
• ⅓ cup pre-packaged crispy onions
  

—

How to make a puff pastry tart with green bean casserole

1. Preheat the oven to 400°F.
   
2. On a lightly floured surface, roll the thawed puff pastry into a 10×10 or 12×12-inch square. Score a ½-inch border around the edges and dock the centre with a fork.
   
3. Transfer the pastry to a baking sheet and bake for 12–15 minutes until puffed and golden. Remove from oven. If the centre has puffed up, gently press it down with the back of a spoon. Set aside.
   
4. In a skillet over medium heat, melt the butter. Add the shallot, rosemary, and mushrooms. Cook for about 8 minutes, stirring occasionally, until softened and lightly browned.
   
5. Deglaze the pan with white wine, scraping up any browned bits. Simmer until the liquid has almost completely evaporated.
   
6. Add the frozen green beans and cook for 2–3 minutes until heated through.
   
7. Stir in the cream and let it simmer for 6–8 minutes until thickened and coating the vegetables. Stir in the parmesan, chives, nutmeg, and cayenne. Remove from heat and let cool slightly.
   
8. Spoon the green bean mixture onto the tart shell, spreading it within the scored border.
   
9. Return the tart to the oven and bake for 3 minutes to heat through.
   
10. Remove from oven and top with crispy onions. Cut into squares and serve immediately.
    

—

Tips for success

• Docking the pastry helps it stay flat in the centre while baking.
  
• Let the green bean filling cool slightly before spreading—it will help keep the pastry crisp.
  
• You can make the filling a day ahead and store it in the fridge; reheat gently before assembling the tart.
  

—

FAQ

Can I use fresh green beans?
Yes. Blanch them in boiling salted water for 2–3 minutes, then drain and cool before using in the recipe.

What can I use instead of white wine?
You can substitute chicken or vegetable stock, or even a splash of apple cider vinegar diluted in water.

Do I have to use cremini mushrooms?
No—white button mushrooms or a mix of wild mushrooms would work well too.How do I reheat leftovers?
Place slices on a baking sheet in a 350°F oven for about 10 minutes, until warmed through.

Green Bean Casserole Tart

Print Recipe

• Author: Andrea Buckett

Ingredients

Units USM

• 1 sheet frozen puff pastry
• 2 tablespoons butter
• 1 shallot, minced
• 175g cremini mushrooms, sliced
• 2 teaspoons finely chopped, fresh rosemary
• 1/4 cup white wine
• 1 tablespoon Dijon mustard
• 1 1/2 cups frozen, cut green beans
• 1/2 cup 35% cream
• 1/4 cup grated parmesan cheese
• 1 tablespoon, chopped, fresh chives
• Pinch of freshly ground nutmeg
• Pinch of cayenne pepper
• 1/3 cup crispy onions (pre-packaged)

Instructions

Thaw the frozen puff pastry overnight in the refrigerator

Preheat oven to 400°F

1. Unroll the pastry or if using a thick square block, roll the pastry out into a 10×10-inch (or 12×12) square. Score the pastry, about ½-inch in from the edge to create a small border around the entire perimeter of the pastry. Dock the inner part of the pastry with a fork.
2. Bake for 12-15 minutes or until the pastry is fully cooked and golden brown. Remove the pastry from the oven. If the middle has puffed up, use the back of a spoon to press it down. Set it aside.
3. In the meantime, place a pan over medium heat. Add the butter. Once melted add the shallot, rosemary and mushrooms. Cook, stirring occasionally for about 8 minutes until the mushrooms are soft and starting to brown.
4. Pour in the wine and scrape any browned bits off the bottom of the pan. Bring to a simmer and reduce the liquid until only a very small amount remains in the pan.
5. Add the green beans, cook for 2-3 minutes until just warmed through.
6. Add the cream. Simmer for 6-8 minutes until the sauce thickens up and the vegetables are well coated in the thick cream. Stir in the parmesan cheese, chives, nutmeg and cayenne. Remove from the heat to cool slightly.
7. Spoon the green bean mixture on to the middle of the tart. Spread it out evenly to the inside of the scored border.
8. Place it back in the oven to heat through for 3 minutes.
9. Remove from the oven. Top it with the crispy onions. Cut the tart into pieces and serve immediately.