French Onion Tartlets!!!
I started with two large sweet onions. They were diced and tossed in a non-stick skillet with butter, thyme, bay leaf, salt and pepper. Cook slow and low for about 45 minutes. The onions will caramelize and reduce down.
After the onions cooked down, I added a quarter cup of a dry white wine. I allowed that to mix in and simmer do to nothing. Next was some apple juice--I'd have preferred cider, but I didn't have it. Simmer that down to nothing. Finally I added some beef stock and simmered that down, about 1/2 cup. You don't want this to actually be soup. A nice thick consistency will be best. Once I had the consistency I wanted, I stirred in a tablespoon of cider vinegar. At the moment, that seemed like a mistake, but the vinegar made the flavors pop later on! I placed the mixture into a bowl and kept it in the fridge for about 3 days before I continued the tartlets the day of the dinner party.
Now...how to make the tarts? Use the recipe here, roll out and cut into small circles with a biscuit cutter, about 2-2 1/2 inch diameter...it might have been 3 inches??? Carefully place the circles into a mini-muffin tins. I forgot, but you should prick the pastry with a fork. You'll need to bake these in the oven for about 15 minutes...350 degrees. They will be puffy and golden brown. Allow to cool.
Each tart shell took about 1 full teaspoon of the onion mixture. I topped each tartlet with a small bit of shredded mozzarella. I would have preferred Gruyere, but I forgot to get some at the store. Put them back in the oven, 350 again, for about 10-15 minutes. This allowed the onion mixture to heat back up and the cheese to melt.
These were tasty little devils. I made enough for at least 12 people, but the 6 of us finished almost all of them off!!! Serve them hot and with a glass of wine. Enjoy.