Savory Puff Pastry Bites with Caramelized Onions and Mushrooms
These savory puff pastry bites hit all the right notes with sweet caramelized onions, marinated Portobello mushrooms, Applewood smoked cheddar cheese, and a hint of fresh thyme.
Although there are several steps required to assemble these tasty morsels, the results are well worth the effort!
Be sure to check out the rest of our easy party appetizer recipes, too!
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Savory Puff Pastry Bites with Caramelized Onions and Mushrooms
It takes some time to caramelize the onions, so this recipe is designed to give you plenty of left overs for your efforts.
What you don’t use in this recipe can be stored in an airtight container in the refrigerator for a week, or they can be frozen for later use.
These puff pastry bites are great to have on hand, because they are absolutely delicious on sandwiches, in soups, or on top of your favorite pizza.
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Another savory appetizer to try are these puff pastry pinwheels.

Ingredients for Bites:
- 1 package frozen puff pastry 2 eggs, beaten
- flour, for rolling
Caramelized Onions:
- 4 large yellow onions 1⁄4 c. unsalted butter
- 3 T. dry white wine salt and pepper, to taste
Marinated Mushrooms:
- 8 oz. sliced baby Portobello mushrooms, cleaned and patted dry 1⁄4 c. Marsala wine
- salt and pepper, to taste
- 2 T. olive oil
- 8 oz. Applewood smoked cheddar, grated
- 3 T. fresh thyme, leaves only
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TIP: Put the cheese in the freezer for 10 minutes before grating for best results.

Puff Pastry Directions:
Step 1: Thaw puff pastry overnight in the refrigerator.
Step 2: In a medium glass bowl, combine mushrooms and Marsala wine. Season with salt and pepper, to taste. Toss to coat.
Marinate for 20 minutes at room temperature. Drain excess moisture before cooking.
Step 3: Heat 2 T. olive oil in a large skillet over medium-high heat. Once oil is hot, add marinated mushrooms and sauté until browned and tender, approximately 5 – 7 minutes.
Remove from heat and transfer to a bowl. Set aside.
Step 4: To caramelize onions, slice off both ends and remove the papery outer layers. Cut onion in half lengthwise (from tip to root).
Then cut each half across the middle to form four sections. Cut each section lengthwise into strips.
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Tip: Don’t cut the onions too thin, or they may burn while cooking.

Step 5: Over medium heat, melt butter in a large skillet with high sides. (For best results, do not use a non-stick pan). Add onions and stir with a wooden spoon until coated with butter.
Step 6: Cook onions over medium heat for approximately 45 – 50 minutes, stirring every 5 minutes or so to ensure they cook evenly and don’t stick to the pan.
The exact cooking time will vary based on several factors, including the age of the onions and how many you cook at one time.
Step 7: Once the onions reach the desired depth of color, add white wine to deglaze the bottom of the pan.
Add more liquid if necessary to scrape up all the brown bits and then salt and pepper the onions, to taste. Remove from heat and let cool in pan until ready to use.
Once cool, transfer any unused onions to an airtight container for future use.
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Step 8: Preheat oven to 375 degrees. Line two large, rimmed baking sheets with parchment paper and set aside.

Step 9: Cut thawed puff pastry dough in half and roll out on a lightly floured surface. With a sharp knife or pizza cutter, cut the puff pastry sheet into 32 equally sized rectangles. (See picture above).
Transfer puff pastry pieces to a prepared baking sheet and place in the freezer for 10 minutes.
Step 10: Repeat the above steps for the other half of the puff pastry.
Step 11: Remove baking sheets from freezer and let sit for a couple of minutes before brushing each piece with the beaten egg.
Step 12: Carefully arrange equal amounts of grated cheddar cheese, caramelized onions and sautéed mushrooms on each piece of puff pastry. Sprinkle each with fresh thyme leaves.
Step 13: Place baking sheets in the preheated oven and bake for 10-15 minutes before rotating each baking sheet to ensure the pastry bites cook evenly.
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Continue cooking until the pastry is golden brown, approximately 8-10 minutes.


Savory Puff Pastry Bites with Caramelized Onions and Mushrooms
These savory puff pastry bites hit all the right notes with sweet caramelized onions, marinated Portobello mushrooms, Applewood smoked cheddar cheese, and a hint of fresh thyme.
Ingredients
- 1 package frozen puff pastry
- 2 eggs, beaten
- flour, for rolling
Caramelized Onions:
- 4 large yellow onions
- 1⁄4 c. unsalted butter
- 3 T. dry white wine
- salt and pepper, to taste
Marinated Mushrooms:
- 8 oz. sliced baby Portobello mushrooms, cleaned and patted dry
- 1⁄4 c. Marsala wine
- salt and pepper, to taste
- 2 T. olive oil
- 8 oz. Applewood smoked cheddar, grated
- 3 T. fresh thyme, leaves only
Instructions
- Thaw puff pastry overnight in the refrigerator.
- In a medium glass bowl, combine mushrooms and Marsala wine. Season with salt and pepper, to taste. Toss to coat. Marinate for 20 minutes at room temperature. Drain excess moisture before cooking.
- Heat 2 T. olive oil in a large skillet over medium-high heat. Once oil is hot, add marinated mushrooms and sauté until browned and tender, approximately 5 - 7 minutes. Remove from heat and transfer to a bowl. Set aside.
- To caramelize onions, slice off both ends and remove the papery outer layers. Cut onion in half lengthwise (from tip to root). Then cut each half across the middle to form four sections. Cut each section lengthwise into strips.
- Over medium heat, melt butter in a large skillet with high sides. (For best results, do not use a non-stick pan). Add onions and stir with a wooden spoon until coated with butter.
- Cook onions over medium heat for approximately 45 – 50 minutes, stirring every 5 minutes or so to ensure they cook evenly and don’t stick to the pan. The exact cooking time will vary based on several factors, including the age of the onions and how many you cook at one time.
- Once the onions reach the desired depth of color, add white wine to deglaze the bottom of the pan. Add more liquid if necessary to scrape up all the brown bits and then salt and pepper the onions, to taste. Remove from heat and let cool in pan until ready to use. Once cool, transfer any unused onions to an airtight container for future use.
- Preheat oven to 375 degrees. Line two large, rimmed baking sheets with parchment paper and set aside.
- Cut thawed puff pastry dough in half and roll out on a lightly floured surface. With a sharp knife or pizza cutter, cut the puff pastry sheet into 32 equally sized rectangles. (See picture). Transfer puff pastry pieces to a prepared baking sheet and place in the freezer for 10 minutes.
- Repeat the above steps for the other half of the puff pastry.
- Remove baking sheets from freezer and let sit for a couple of minutes before brushing each piece with the beaten egg.
- Carefully arrange equal amounts of grated cheddar cheese, caramelized onions and sautéed mushrooms on each piece of puff pastry. Sprinkle each with fresh thyme leaves.
- Place baking sheets in the preheated oven and bake for 10-15 minutes before rotating each baking sheet to ensure the pastry bites cook evenly. Continue cooking until the pastry is golden brown, approximately 8-10 minutes.
Notes
1. Put the cheese in the freezer for 10 minutes before grating for best results.
2. Don’t cut the onions too thin, or they may burn while cooking.
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Nutrition Information:
Yield: 64 Serving Size: 1Amount Per Serving: Calories: 42Total Fat: 3gSaturated Fat: 1gTrans Fat: 0gUnsaturated Fat: 1gCholesterol: 11mgSodium: 42mgCarbohydrates: 3gFiber: 0gSugar: 1gProtein: 1g
Nutrient values are only estimates provided by online calculators. Various factors can change the nutritional information in any given recipe.
For more mouth-watering appetizers:
Brilliant Bites: 75 Amazing Small Bites for Any OccasionMartha Stewart’s Appetizers: 200 Recipes for Dips, Spreads, Snacks, Small Plates, and Other Delicious Hors d’ Oeuvres, Plus 30 Cocktails: A Cookbook
Party-Perfect Bites: Delicious recipes for canapés, finger food and party snacks
Graze: Inspiration for Small Plates and Meandering Meals: A Charcuterie Cookbook
Don’t miss out on our other family friendly recipes!
Oh my goodness, these look so good! You have some of my favorite flavors packed into a flaky bite!
These look delicious and easy to make! Thanks for the great idea
Your Puff Pastry Bites will be awesome! Thanks so much for sharing with us at Full Plate Thursday and you have a great week!
Miz Helen