Mushroom caramelized onion cheese appetizer

[feather]

This just looks so good!

littlespicejar.com/gruyere-mushroom-caramelized-onion-bites/?utm_campaign=shareaholic&utm_medium=facebook&utm_source=socialnetwork&fbclid=IwAR3Enf2-HSARhypwaiBiy8l2imLE37kEWjCu33N7mYqoKOaRQw4MXpABIyM

I've got canned caramelized onions, and frozen mushrooms w/cheese and gruyere cheese. I even have some puff pastry frozen that I made, but I'm thinking I'll like it if I put it instead on some more easily made foccacia, in small squares.

Ingredients:

4 tablespoons salted butter, divided
2 tablespoons vegetable oil, divided
5-6 ounces crimini or button mushrooms, sliced
2 medium yellow onions, thinly sliced
1/4 teaspoon dried thyme
1 tablespoon sugar
1 1/2 tablespoon balsamic vinegar
1/4 teaspoon garlic powder
salt and pepper, to taste
4 ounces grated gruyere cheese (I used applewood smoked gruyere)
1 package (1 pound) frozen puff pastry, thawed
1 egg, lightly beaten

I'm going to make it with rye flour and sourdough AND yeast. No egg, no sugar, but I bet it will be good that way too.

[susannah]

It looks pretty amazing. I definitely want to try this!

[feather]

I had this for dinner. It was like mini pizzas, mushroom caramelized onion and cheese. Very nice. Dh liked it too and he said it reminded him of pizza.