Caramelized Onion, Mushroom and Gruyere Tart

I can't believe I am just getting around to posting this one.  I LOVED this little tart. We used this as an appetizer but they would be good as a snack too.  You could make some up ahead of time and keep them in the refrigerator.  If the kids like them they might be a nice little lunch box treat as well.

Caramelizing the onions and mushrooms is key here.  It takes about 20 minutes or so over low heat but it's so worth it.

The Gruyere cheese adds the perfect bite to the onions and mushrooms.  If you're not sure about this cheese it's in the Swiss cheese family.  Definitely worth trying if you've never had it before. A friend of mine tried these and he adamantly does not like vegetables, I think he just tried it to be polite but he ended up really liking it!  Give it a try, I think you'll like it too. 

Caramelized Onion, Mushroom and Gruyere Tart

Recipe found at Tracey's Culinary Adventures originally from Avec Eric

Ingredients

• 1/4 cup olive oil
• 2 large onion, thinly sliced
• 1 small container crimini mushrooms, or button mushrooms - diced
• 1 small clove garlic
• 1/4 tsp thyme
• 2 sheets frozen puff pastry, thawed
• 1/2 cup grated Gruyere cheese

Cooking Directions

1. Lightly flour a surface and place the thawed puff pastry on it. Use your fingers to make sure the crease's are smoothed over and the pastry sheet is free from tears.
2. Use a 3 1/2 inch biscuit cutter to cut as many holes as possible in the pastry puff sheets.
3. Preheat the oven to 450 degrees.
4. Line a cookie sheet with parchment paper and place the rounds on the prepared cookie sheets.
5. Refrigerate until ready to use.
6. In a large frying pan add the oil and turn the heat to medium. Add the onions and mushrooms and cook for about 10 minutes. Reduce the heat to medium low and cook for another 20-30 minutes or until the onions and mushrooms are caramelized.
7. Remove the cookie sheets from the refrigerator and top each puff pastry circle with enough onion and mushroom mixture to cover the top of the puffs. Add the shredded Gruyere on top and place in the oven for 13-17 minutes or until the edges of the puff pastry are a nice golden brown and the cheese is melted and bubbly.
8. Remove from the oven and let cool slightly before serving.